Interstate 25 in Colorado

Interstate 25/U.S. Route 87
Route information
Maintained by CDOT
Length:	305.040 mi[1] (490.914 km)
Major junctions
South end:	I-25 / US 85 / US 87 near Trinidad
	US 160 from Trinidad to Walsenburg US 50 in Pueblo SH 470 / E-470 in Lone Tree I-225 in Denver US 285 in Denver US 40 / US 287 in Denver I-70 / US 6 / US 85 in Denver I-76 in North Washington I-270 / US 36 in Welby E-470 in Broomfield
North end:	I-25 / US 87 near Wellington
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Colorado State Highways Interstate U.S. State Scenic ← US 24 SH 26 → ← SH 86 SH 88 →

In the U.S. state of Colorado, Interstate 25 follows the north–south corridor through Colorado Springs and Denver. The highway enters the state from the north near Carr and exits the state near Starkville. The highway also runs through the cities of Fort Collins, Loveland, and Pueblo. The route is concurrent with U.S. Highway 87 through the entire length of the state. I-25 replaced U.S. Highway 87 and most of U.S. Highway 85 for through traffic.

Historical nicknames for this route have included the Valley Highway (through Denver), Monument Valley Highway (through Colorado Springs), and the Pueblo Freeway (through Pueblo). Within El Paso County, the route has been dedicated as the Ronald Reagan Highway.^[2][3] In Pueblo County, the route is called John F. Kennedy Memorial Highway.

Interstate 25 is also considered to be part of the unofficial Pan-American Highway.^[4]

Route description

New Mexico state line to Pueblo

Northbound I-25 between Colorado Springs and Denver.

Following the Santa Fe Trail from New Mexico, Interstate 25 enters Colorado as a typical four-lane Interstate Highway, where its entire route in Colorado lies close to the east side of the Rocky Mountains. The route turns from north to west-northwest as I-25 serves Wootton. After leaving Wootton, I-25 turns back up north and bypasses near the east side of the Trinidad Lake State Park, home of the Trinidad Lake.

Trinidad, a city near the Trinidad Lake, is the first major city that lies along I-25. For the next 30 miles (48 km), I-25 continues north through the rural areas of Colorado until it reaches the small city of Walsenburg, where the business route - I-25 Bus. - junctions with U.S. Highway 160. I-25 then continues in a north-northwest direction until it bypasses the Orlando Reservoir, then turns north from there until it reaches Colorado City. In Colorado City, I-25 interchanges with the east end of the Frontier Pathways Scenic and Historic Byway (SH 165) at exit 74.

After leaving the city, I-25 follows in a north-northeast orientation until it reaches the St. Charles Reservoir just before entering the city of Pueblo, with the first exit within the southern city limits of Pueblo at exit 94.^[5] The Arkansas River in Pueblo serves as a feeder to the Lake Pueblo State Park, home of the Pueblo Lake, which is located to the west of the western city limits of Pueblo.^[6]

Pueblo to Denver

I-25 during rush hour in the largest city I-25 serves, Denver, looking East toward Downtown Denver.

After leaving Pueblo, I-25 continues up north with the Union Pacific Railroad line paralleling closely to the route on the right side after interchanging with Porter Draw at exit 106. By exit 119, the Fountain Creek joins along and travels parallel with I-25, and continues all the way to the Fountain Creek Regional Park in Widefield. I-25 gradually turns from a general north direction to the north-northwest and serves the census-designated place of Buttes at exit 122.

Cheyenne Mountain, as seen from I-25 near Fort Carson. Note the communications antennas at the summit, which are radio antennas for stations broadcasting in Colorado Springs.

As soon as US 85 leaves I-25 at exit 128, I-25 enters the city limits of Fountain. Basically, I-25 serves as the border between the western city limits of Fountain on the east side of I-25 and Fort Carson on the west side. Exit 132 (SH 16) serves the north side of the Fountain Creek Regional Park as well as the entrance to Fort Carson and connects to SH 21 (Powers Boulevard), the eastern bypass for the Colorado Springs metro area. By the time I-25 reaches exit 138, the route crosses into the city limits of Colorado Springs, where the stack interchange with US 24 at exit 139 serves the Evergreen Cemetery and Prospect Lake. I-25 turns west at exit 140, along with the Fountain Creek, where it interchanges with US 85, US 87, and I-25 Bus. I-25 again turns back north by exit 141. Swinging around the west side of downtown Colorado Springs at exit 142,^[5] and to the north of the city lies the Colorado College, and is served at exit 143 - Uintah Street. Continuing north and northeast, the highway intersects the north terminus of I-25 Bus. and US 85. The interstate leaves Colorado Springs between exits 153 and 156, where I-25 enters the United States Air Force Academy, going through the east side of the institution.

Map showing I-25 and nearby freeways and major highways in the Denver Metropolitan area

I-25 leaves El Paso County and enters Douglas County at Monument Hill, elevation 7,352 feet, north of Monument. I-25 then continues north through more rural and hilly areas east of the Rocky Mountains until reaching Castle Rock at exit 181. I-25 continues through rural and hilly portions of Douglas County until interchanging with E-470, the partial beltway of Denver as the toll road serves the Centennial Airport and the much larger Denver International Airport.

After entering Arapahoe County, I-25 cuts through the Denver Technological Center (DTC) between Dry Creek Road and Belleview Avenue (exits 196-199). I-25 enters Denver at the I-225 interchange, a spur that detours motorists to I-70 through Aurora, at exit 200. I-25 turns in an westerly direction between Evans Avenue (Exit 203) and Colorado Boulevard (Exit 204). University of Denver lies just to the south of the interstate at Exit 205. It then turns back north after Exit 207. I-25 curves around the west side of downtown Denver,^[5] where it can be accessed by I-70 Bus. at exit 210.^[5] I-25 then interchanges with I-70 at exit 214 right before leaving the City and County of Denver. ^[6]

Denver to Wyoming state line

As I-25 leaves Denver, the route continues up north through unincorporated areas of Adams County and interchanges with I-76, I-270, and the Denver-Boulder Turnpike (US 36). Due to the complexity of this triangle-shaped interchange, it was known to be one of many malfunction junctions throughout the United States. Beyond that interchange, the interstate enters the northern suburbs of the Denver metro area, such as Thornton and Northglenn, and at exit 220, I-25 slips its way through a narrow path between the Badding Reservoir (west side) and the Croke Lake (east side). Development begins to drop off after exit 223 (120th Avenue) after continuing north into Westminster and eastern Broomfield.

At exit 228, I-25 interchanges with the northern termini of E-470 and Northwest Parkway at a stack interchange, with the Larkridge Mall just to the north, served by 160th Avenue (SH 7). As I-25 continues north, it moves through rolling farm and grasslands with the Front Range and high mountains clearly visible to the west while passing through a medley of lakes and reservoirs. It stays generally flat with few moderate climbs in elevation, while also serving smaller cities like Dacono and Firestone to the east and Longmont to the west. This stretch of I-25 in northern Colorado also has large amounts of truck traffic between SH 7 and Wyoming. After some time in the rural farmlands, the interstate enters the Fort Collins/Loveland metro area at exit 255, serving Loveland and Greeley to the east at exits 255 and 257, and continuing north to the Fort Collins city limits south of Harmony Road. The highway runs on the eastern side of Fort Collins, serving Colorado State University at exits 268 and 269 (which is also the most direct route to downtown). After exit 271, I-25 leaves Fort Collins and rolls into more rural grasslands past Wellington. Exits also become few and far between from here to Wyoming as well after gradually turning north-easterly towards the state line.^{[5] [6]}

History

Ancestors and early freeways

Colorado had begun planning of a modern inter-city route along the Front Range as early as 1944, well before the national movement toward an Interstate Highway system.

State Highway 1, an unpaved road, was completed between Denver and Pueblo by 1919. Average travel time between Pueblo and Colorado Springs on this route was approximately 2.5 hours (or a full 8.5 hours from Pueblo to Denver). This route was upgraded with the help of the federal government to become US 85 and US 87 by 1930, now paved in concrete and shortening the travel time between Pueblo and Colorado Springs to just one hour.

The cities of Denver (in 1948) and Pueblo (in 1949) were first to begin building multi-lane highway segments along the route of what would eventually become Interstate 25. Construction follows an earlier segment of the Colorado and Southern Railway. Denver's segment was originally known as the Valley Highway and was completed by 1958. The city of Colorado Springs followed a similar theme with their Monument Valley Freeway, begun in 1955 and completed by July 1960. Pueblo's section — the Pueblo Freeway - was complete by July 1959.^[3]

Interstate completion

As the national Interstate Highway System began to take shape, actual "inter-state" connections began to be made. Wyoming came first in 1964, building a 9-mile (14 km) link north to Cheyenne that was connected to Colorado's 17-mile (27 km) stretch.

Linking to New Mexico in the south would prove more problematic as the planned route had to stretch over Raton Pass, and its accompanying 1,800-foot (550 m) elevation change, within just 13 miles (21 km). Once again, US 85 and US 87 were used, but it had to be re-graded in places to meet Interstate design guidelines. Construction began in 1960, with a link to the city of Trinidad completed by 1963. The Trinidad Segment (as CDOT now calls the Raton Pass span) was not fully completed until 1968.

The final segment of the Colorado portion of Interstate 25, connecting the cities of Walsenburg and Trinidad, was completed during 1969. This meant that four lanes of high-speed, nonstop freeway were finally open for a full 305 miles (491 km) from New Mexico north to Wyoming.^[3][7]

Modern expansion

As both population and traffic increased in Colorado during the 1990s and 2000s, the Colorado Department of Transportation has planned and completed major improvements for the city corridors along I-25.

T-REX (Denver)

T-REX Logo

The first of these was Transportation Expansion (T-REX), which widened and expanded nearly 17 miles (27 km) of both I-25 and the I-225 bypass in the Denver Metropolitan Area as well as adding various pedestrian and aesthetic improvements. T-REX was also instrumental in expanding Denver's RTD light rail lines to connect outlying communities beyond the city and county of Denver, adding 19 miles (31 km) of new routes.^[7][8]

Starting in early 2004, the T-REX project was completed during 2006 at a cost of US$1.67 billion, under its projected budget and two years ahead of its originally scheduled conclusion. It has been hailed as a "model for other cities to follow" and "ahead of the curve nationally" by federal transportation and transit authorities.^[8]

COSMIX (Colorado Springs)

COSMIX Logo

As T-REX began to wrap up, CDOT's next major effort began with Colorado Springs Metro Interstate Expansion (COSMIX). It could be argued that COSMIX was even more important to Colorado's interests than T-REX had been, since the Colorado Springs corridor of I-25 had seen immense growth over the past four decades, and experienced major choke points all along the 16-mile corridor from Exit 135 (Academy Blvd) in the south to Exit 151 (Briargate Blvd) in the north. Originally carrying around 8500 vehicles per day in 1960, usage of the former Monument Valley Freeway had grown to an average of 100,000 vehicles per day by 2005.^[9]

The major goals of COSMIX, which began in 2005 and was completed a year and four days ahead of schedule at the very end of December, 2007, were a general expansion and widening of the corridor to three lanes in each direction throughout the city, as well as the reconstruction of two main interchanges (at Bijou Street near downtown Colorado Springs, and at Rockrimmon Boulevard and North Nevada Avenue in the city's growing north side).^[10] Originally estimated at $225 million, on delivery COSMIX cost only $150 million, approximately $20 million of which involved land acquisition costs. With respect to schedule and budget, then, COSMIX proved a superbly successful project, the result of the decision by the project manager and project engineer, both young women, to negotiate with CDOT for six months' extra detail planning time up front. Their efforts paid off in an effective reduction of the overall work schedule by 18 months and 4 days.

Though CDOT's role in COSMIX was complete, the City of Colorado Springs continued its own independent project to rebuild the Cimarron Street (US 24) bridge and interchange. This work was functionally complete (allowing limited traffic) by May 2008, with full completion achieved by September 2008.^[11]

CDOT has now finished construction in the Colorado Springs area where the 12 mile segment from Woodmen Road (exit 149) to Monument (exit 161) was expanded to six lanes and includes additional auxiliary lanes at busy interchanges. The Air Force Academy interchange (exit 156) was reconfigured to include just one exit, instead of A/B, and features two new roundabouts for North Gate Boulevard. The widening and paving was completed in December 2014.^[12]

Future

A new "lane balance" project has begun in northern Douglas County (Lone Tree) from Lincoln Avenue to County Line Road, where CDOT will expand the highway to eight lanes to eliminate the current six lane bottleneck from drivers coming from Castle Rock to the south into Denver. This will connect the existing eight lanes from RidgeGate Parkway to the terminus of the previous T-REX project from years earlier at County Line Road.^[13]

Toll lanes will be added along I-25 from US 36 (exit 217) to 120th Avenue (exit 223) in the Thornton area starting in October 2013. Two lanes (one north, one south) will be operational for drivers wishing to cut through traffic by paying a toll, similar to the US 36 project. The highway will have to be expanded and reconstructed to add the additional lanes to the six lane configuration currently in place. The project should be complete by October 2015.^[14]

There is much controversy surrounding the future of Interstate 25 in northern Colorado (SH 7 in Broomfield to SH 14 in Fort Collins). Suggestions from adding toll lanes to general expansion to six lanes from the two lane bottleneck at SH 66 to SH 14 and adding multi-modal transportation options have been discussed. The future of the highway remains in question as funding is limited, and agreement is limited as well. The I-25 corridor in Weld and Larimer counties is becoming increasingly heavy with traffic, and something will have to be done soon.^[15]

The seven mile segment of I-25 through Pueblo also is in need of reconstruction, and the subject is of much controversy in southern Colorado. On the agenda are expanding the now 60-year-old interstate to six lanes, adding additional auxiliary lanes, and improving many interchanges to bring them up to current standards. The road segment from exit 101 (US 50/SH 47) to exit 94 (SH 45/Pueblo Boulevard) is currently the oldest section of I-25 in the state, and has not been upgraded since the 1950s, minus minor alterations and paving. The controversy surrounds the straightening of the highway through the city and the possible removal of several businesses around the downtown area and the historic district. ^[16]

Exit list

County	Location	mi[1]	km	Exit	Destinations	Notes
Colorado–New Mexico line		0.000	0.000		I-25 / US 85 / US 87 south – Albuquerque	Continuation into New Mexico
				460	Truck weigh station	Northbound entrance extends into Colorado; exit number is based on New Mexico mileage
Las Animas	​	2.134	3.434	2	Wootton
	​	5.597	9.007	6	Gallinas
	​	7.529	12.117	8	Springcreek
	​	11.013	17.724	11	Santa Fe Trail – Starkville
	Trinidad	13.000	20.921	13A	Van Buren Street
		13.311	21.422	13B	SH 12 west (Main Street) – Cuchara, La Veta
		13.906	22.380	14	Commercial Street
		14.859	23.913	15	SH 239 north / US 160 east / Goddard Avenue, Kit Carson Trail	South end of US 160 overlap
	​	17.728	28.530	18	El Moro Road
	​	22.906	36.864	23	Hoehne Road
	​	26.858	43.224	27	Ludlow
	​	30.464	49.027	30	Aguilar Road
	​	34.090	54.863	34	Aguilar
Huerfano	​	40.485	65.154	41	Rugby Road
	​	41.930	67.480	42	Pryor
	Walsenburg	49.000	78.858	49	I-25 Bus. north to US 160 west – Walsenburg, Alamosa
	​	50.054	80.554	50	SH 10 east (US 160 west) – La Junta	North end of US 160 overlap
	​	52.321	84.202	52	I-25 Bus. south / SH 69 west to US 160 west – Gardner, Westcliffe
	​	55.000	88.514	55	Airport Road
	​	56.000	90.123	56	Redrock Road
	​	58.727	94.512	59	Butte Road
	​	60.084	96.696	60	Huerfano
	​	64.046	103.072	64	Lascar Road
	​	66.749	107.422	67	Apache
Pueblo	Colorado City	71.264	114.688	71	Graneros Road
		74.367	119.682	74	SH 165 west – Colorado City, Rye, San Isabel
	​	77.267	124.349	77	Abbey Road, Hatchet Ranch Road
	​	83.461	134.317	83	Brantzwell
	​	86.938	139.913	87	Verde Road
	​	87.921	141.495	88	Burnt Mill Road
	​	90.625	145.847	91	Stem Beach
	Pueblo	94.769	152.516	94	SH 45 north (Pueblo Boulevard)
		95.403	153.536	95	Illinois Avenue	Southbound exit only
		95.901	154.338	96	Minnequa Avenue, Indiana Avenue
		96.673	155.580	97A	Central Avenue to Northern Avenue
		97.447	156.826	97B	Abriendo Avenue
		97.691	157.218	98A	US 50 Bus. east – La Junta
		98.545	158.593	98B	To SH 96 / 1st Street
		98.806	159.013	99A	To SH 96 / 6th Street	Southbound exit and northbound entrance (from Bradford Avenue)
		99.334	159.863	99B	13th Street, Santa Fe Avenue
		99.950	160.854	100A	US 50 east – La Junta, Pueblo Memorial Airport	South end of US 50 overlap
		100.681	162.030	100B	29th Street
		101.389	163.170	101	US 50 west / SH 47 east – Cañon City	North end of US 50 overlap
		102.160	164.411	102	Eagleridge Boulevard
	​	103.896	167.204	104	Eden
	​	106.075	170.711	106	Porter Draw
	​	108.000	173.809	108	Purcell Boulevard – Pueblo West
	​	110.238	177.411	110	Pinon
	​	114.000	183.465	114	Young Hollow
	​	115.831	186.412	116	County Line Road
El Paso	​	118.843	191.259	119	Rancho Colorado Boulevard
	Fountain	121.459	195.469	122	Pikes Peak International Raceway
		123.189	198.253	123	Clear Spring Ranch	Exit does not sign this destination
		124.564	200.466	125	Ray Nixon Road
		127.860	205.771	128	US 85 north – Fountain	North end of US 85 overlap
		131.653	211.875	132	SH 16 east (Mesa Ridge Parkway) to SH 21 – Fort Carson Gate 20	Signed as exits 132A (SH 16) and 132B (Ft. Carson) southbound
	​	135.262	217.683	135	South Academy Boulevard – Colorado Springs Airport
	Colorado Springs	137.752	221.690	138	Lake Avenue, Circle Drive
		138.742	223.284	139	US 24 east (Martin Luther King Jr. Bypass) – Limon	South end of US 24 overlap
		139.747– 139.869	224.901– 225.097	140	SH 115 south (Nevada Avenue, Tejon Street) – Cañon City
		141.139	227.141	141	US 24 west (Cimarron Street) – Manitou Springs, Pikes Peak	North end of US 24 overlap
		141.849	228.284	142	Bijou Street – Downtown Colorado Springs
		142.832	229.866	143	Uintah Street
		143.520	230.973	144	Fontanero Street
		144.622	232.747	145	Fillmore Street
		146.074	235.083	146	Garden of the Gods Road
		147.245– 148.030	236.968– 238.231	148	Nevada Avenue (US 85 south), Corporate Drive, Rockrimmon Boulevard	South end of US 85 overlap
		148.830	239.519	149	Woodmen Road
		150.303	241.889	150	North Academy Boulevard
		151.660	244.073	151	Briargate Parkway
		152.899	246.067	153	To SH 21 (Powers Boulevard) / InterQuest Parkway – Black Forest
	Air Force Academy	155.930	250.945	156	North Gate Boulevard – North Entrance Air Force Academy
	​	158.199	254.597	158	Baptist Road
	Monument	160.763	258.723	161	SH 105 – Monument, Palmer Lake
El Paso–Douglas county line	​	163.321	262.840	163	County Line Road – Palmer Lake
Douglas	​	167.464	269.507	167	Greenland
	​	171.820	276.517	172	Upper Lake Gulch Road	Primary backup for Spruce Mountain Road. The road Between Exit 173 and Spruce Mountain Road was Numbered SH 18 until 2001 and is current CR 56.
	Larkspur	172.307	277.301	173	Spruce Mountain Road	Southbound exit and northbound entrance. Numbered SH 1 Between about 1920 to 1968.
	​	173.791	279.690	174	Tomah Road
	Castle Rock	180.808	290.982	181	Plum Creek Parkway
		181.853	292.664	182	Wilcox Street, Wolfensberger Road
		184.212	296.460	184	US 85 north (Meadows Parkway) / SH 86 east / Founders Parkway	North end of US 85 overlap
	​	186.935	300.843	187	Happy Canyon Road
	​	188.486	303.339	188	Castle Pines Parkway
	Lone Tree	192.096	309.149	192	RidgeGate Parkway	Opened on May 20, 2009[17]
		192.990	310.587	193	Lincoln Avenue
		194.314	312.718	194	SH 470 west / E-470 east – Grand Junction, Limon	E-470 exit 1.
Douglas–Arapahoe county line	Lone Tree–Centennial line	195.130	314.031	195	County Line Road
Arapahoe	Centennial	196.141	315.658	196	Dry Creek Road
		197.188	317.343	197	SH 88 east (Arapahoe Road)	South end of SH 88 overlap
	Greenwood Village	198.292	319.120	198	Orchard Road
		199.384	320.877	199	SH 88 west (Belleview Avenue)	North end of SH 88 overlap
City and County of Denver		200.093	322.018	200	I-225 north to I-70 – Limon, Aurora	I-225 exits 0A-B; directional T interchange.
		201.578	324.408	201	US 285 south / SH 30 east (Hampden Avenue)
		202.640	326.117	202	Yale Avenue
		203.537	327.561	203	Evans Avenue
		204.037	328.366	204	SH 2 (Colorado Boulevard)
		205.057	330.007	205	University Boulevard
		205.919	331.395	206	Downing Street, Washington Street, Emerson Street	Downing St. not signed southbound
				207A	Lincoln Street, Broadway	Lincoln St. not signed southbound
				207B	Santa Fe Drive to SH 26	Northbound exit and southbound entrance
					US 85 south (Santa Fe Drive)	South end of US 85 overlap; southbound exit and northbound entrance
		207.641– 207.990	334.166– 334.727	208	SH 26 (Alameda Avenue)	Southbound exit and northbound entrance; northbound access is via exit 207B
		209.210	336.691	209	US 6 west (6th Avenue) – Lakewood	South end of US 6 overlap; signed as exits 209A (east) and 209B (west)
		209.479	337.124	209C	8th Avenue
		210.310	338.461	210A	US 40 / US 287 (Colfax Avenue) – Downtown Denver
		210.415	338.630	210B	Auraria Parkway	Northbound exit and southbound entrance
		210.532	338.818	210C	17th Avenue	Northbound exit and entrance; southbound access is via exit 211
		211.109	339.747	211	23rd Avenue, 20th Avenue	20th Ave. not signed northbound
		211.464	340.318	212A-B	Speer Boulevard – Downtown Denver	Signed as exits 212A (south) and 212B (north)
		212.096	341.335	212C	20th Street
					I-25 HOV/toll lanes	South end of reversible HOV/toll lanes
				—	19th Street	Southbound exit and northbound entrance for HOV/toll lanes only
		212.769	342.419	213	Park Avenue, West 38th Avenue
		213.625– 213.739	343.796– 343.980	214A	I-70 (US 6 east/US 85 north) – Limon, Grand Junction	North end of US 6/US 85 overlap; locally known as The Mousetrap; I-70 exit 274
		213.964	344.342	214B	48th Avenue	Southbound exit only
Adams	North Washington	215.244	346.402	215	58th Avenue
		216.301	348.103	216A	I-76 east – Fort Morgan	Northbound exit and southbound entrance; I-76 exit 5
	Welby	216.397– 216.779	348.257– 348.872	216B	SH 224 (70th Avenue) / I-76 west – Grand Junction	Signed as exit 216 southbound; SH 224 not signed southbound; I-76 exit 5
				—	SH 224 (70th Avenue)	Northbound exit and southbound right entrance for HOV/toll lanes only
		217.006	349.237	217	I-270 east / US 36 – Limon, Aurora, Westminster, Boulder	No access to I-270/US 36 east northbound; southbound signed as exits 217A (west) and 217B (east); I-270 exit 0 to I-25 north.
				—	US 36 west – Boulder	Southbound right exit and northbound entrance for HOV/toll lanes only
					I-25 HOV/toll lanes	North end of reversible HOV/toll lanes
	Thornton	218.463	351.582	219	84th Avenue – Federal Heights
		219.815	353.758	220	Thornton Parkway
	Northglenn	221.027	355.708	221	104th Avenue – Northglenn	Former SH 44
		223.049	358.963	223	SH 128 west (120th Avenue)
	Westminster	225.000	362.102	225	136th Avenue
		226.085	363.849	226	144th Avenue
City and County of Broomfield		227.745	366.520	228	E-470 east / Northwest Parkway west – Limon, Broomfield	E-470/NW Pkwy. exit 47
		229.107	368.712	229	SH 7 – Lafayette, Brighton
Weld	​	232.094	373.519	232	Dacono, Erie
	​	235.114	378.379	235	SH 52 – Dacono, Frederick, Fort Lupton
	​	240.114	386.426	240	SH 119 west – Firestone, Longmont
	​	243.148	391.309	243	SH 66 – Longmont, Lyons
	Mead	245.217	394.639	245	Mead
	Johnstown	250.241	402.724	250	SH 56 west – Berthoud
		252.261	405.975	252	SH 60 east – Johnstown, Milliken
Larimer	​	254.216	409.121	254	To SH 60 west – Campion
	​	255.272	410.820	255	SH 402 west – Loveland
	Loveland	257.305	414.092	257	US 34 – Greeley, Loveland
		259.309	417.317	259	Crossroads Boulevard – Fort Collins-Loveland Airport
	​	262.298	422.128	262	SH 392 – Windsor, Fort Collins
	Fort Collins	265.314	426.981	265	Harmony Road
		268.475	432.069	268	Prospect Road
		269.370– 269.570	433.509– 433.831	269A-B	SH 14 – Fort Collins, Ault	Signed as exits 269A (east) and 269B (west)
		271.373	436.733	271	Mountain Vista Drive
	Wellington	277.884	447.211	278	SH 1 south – Wellington
	​	281.338	452.770	281	Owl Canyon Road
	​	287.550	462.767	288	Buckeye Road
Weld	​	292.583	470.867	293	Carr
	​	305.040	490.914		I-25 / US 87 north – Cheyenne, Casper	Continuation into Wyoming
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus       ETC       HOV only       Incomplete access

References

1. Colorado Department of Transportation, Highway Data, accessed October 2007: note that not every interval between mileposts is exactly a mile, explaining why more exits than expected are at the exact milepost
2. Ronald Reagan Presidential Foundation & Library Archived July 25, 2008, at the Wayback Machine.
3. "Interstate 25". Dot.state.co.us. Retrieved 2011-11-27.
4. Sierra County Economic Development Organization. "Transportation and Highways". Archived from the original on September 7, 2007. Retrieved February 2008. Check date values in: |access-date= (help)
5. The Road Atlas (Map). Rand McNally. 2006. p. 32.
6. Google Maps street maps and USGS topographic maps, accessed February 2008 via ACME Mapper
7. Kuennen, Tom, ed. Interstate 50: 50 Years of the Dwight D. Eisenhower National System of Interstate and Defense Highways. 2006: Faircount. pp 118-119. ISBN unavailable.
8. "Metro Denver's multi-modal T-REX takes last step - Metro Denver Economic Development Corporation". Metrodenver.org. Retrieved 2011-11-27.
9. Kuennen, Tom, ed. Interstate 50: 50 Years of the Dwight D. Eisenhower National System of Interstate and Defense Highways. 2006: Faircount. pp 118-119. ISBN unavailable.
10. "Progress of Project". Cosmixproject.com. Archived from the original on January 13, 2010. Retrieved 2011-11-27.
11. Pikes Peak Transportation Archived November 1, 2007, at the Wayback Machine.
12. http://www.koaa.com/news/i-25-expansion-project-nears-completion/
13. "I-25 Lincoln Avenue to County Line Road Lane Balancing Project Has Begun". coloradodot.info.
14. "Project Overview". coloradodot.info.
15. "North I-25 (Denver to Wyoming)". coloradodot.info.
16. Shanna Lewis. "Expansion Plans for I-25 in Pueblo". krcc.org.
17. "RidgeGate Parkway Interchange Brings Traffic Relief to Douglas County" (PDF). Southeast Connections. June 2009. Retrieved 2011-11-27.

External links

Route map: Bing / Google

• Colorado Department of Transportation (CDOT)
• COSMIX (CDOT project; website no longer being updated)
• South I-25 Corridor: Lincoln Avenue through Castle Rock (CDOT project)
• The North Forty (CDOT project)
• I-25 Trinidad (CDOT project)
• The New Pueblo Freeway (proposed CDOT project)