Interstate 25 - Colorado


Interstate 25 is the main north-south freeway corridor through Colorado. Part of the Camino Real High Priority Corridor, Interstate 25 connects Mexico with Canada via ports at El Paso and a connection with Interstates 15 and 90 to Canada. The freeway is undergoing several improvements as part of this corridor strategy, including the massive T-REX improvement project in Denver, upgrades through Colorado Springs, and planned expansion of the freeway to six lanes along the Front Range.

Once completed in Colorado, Interstate 25 replaced U.S. 87. That route is silently merged with Interstate 25 for most of its length in Colorado. There are a handful of U.S. 87 shields, and a fun game may be to find the three or so shields for U.S. 87 that remain on Interstate 25. U.S. 87 does not appear on any overhead signs in Colorado.

Interstate 25 Colorado Highway Guides


Interstate 25 was the first mainline Interstate highway to be completed in Colorado. It was also the first segment of freeway to be built in Colorado. Known as the Valley Highway (U.S. 87), the first two-mile section of future Interstate 25 began construction in August, 1948, and was completed in 1950. By 1958, the Valley Highway through the Denver metropolitan area was completed, only two years after the Interstate Highway Act was signed by President Eisenhower. Another pre-Interstate section of Interstate 25 that was grandfathered into the system included a 9.2-mile segment of freeway in Pueblo (construction began in 1949 and was completed in 1958). A notable milestone in the construction process was the extension of Interstate 25 into Wyoming on October 11, 1964. This date marked the first occasion when a Colorado Interstate actually crossed state lines and entered another state. A 26-mile segment of Interstate 25 heading north from Wellington opened on that date.

Segment Location/Description Mileage (Approximate) Completion
Trinidad/Raton Pass From Raton Pass at New Mexico Line north to south edge of Trinidad 13 miles 1966
Trinidad Elevated portion, approximately three miles in length 3 miles 1963
Trinidad to Walsenburg From Trinidad north to Walsenburg. This was the last segment of I-25 to be completed in Colorado ; it was dedicated on 9/21/69 21 miles 1969
Walsenburg Constructed as the Walsenburg Bypass 3 miles 1964
Walsenburg to Colorado City Connects north end of Walsenburg bypass with Colorado 165 interchange 22 miles 1968
Colorado City From Colorado 165 interchange in Colorado City north to Pueblo Boulevard 20 miles 1965
Pueblo Original urban freeway segment of Interstate 25 near downtown Pueblo ; includes 0.6-mile long bridge over Arkansas River 9.2 miles July 1959
South of Pueblo to Monument From south of Pueblo to north of Colorado Springs; connected pre-existing segments in Pueblo and Colorado Springs 67 miles 1961
Colorado Springs Original urban freeway segment of Interstate 25 near downtown Colorado Springs 12 miles July 1960
Monument Hill Monument to Larkspur 12 miles 1965
Larkspur to Castle Rock   9 miles 1968
Castle Rock to Denver Connects Castle Rock with Valley Highway in Denver 25 miles 1963
Denver From Evans Avenue north to 48th Avenue . This urban freeway was first section of Interstate 25 built; it was known as the Valley Highway (U.S. 87) 11.2 miles November 1958
Denver Northside From the north end of the Valley Highway (at 48th Avenue ) north to 58th Avenue 0.5 mile 1961
Denver north From 58th Avenue to Colorado 7 14 miles 1963
Longmont Area From Colorado 7 to Colorado 66 14 miles 1961
North of Denver From Colorado 66 to U.S. 34 14 miles 1963
Fort Collins Area U.S. 34 to (now former) Colorado 68 ( Harmony Road ) 8 miles 1965
Colorado 68 to North of Wellington Harmony Road in Fort Collins to Buckeye Road (at that time, Interstate 25 became continuous from Walsenburg north to Colorado/Wyoming border) 23 miles 1968
North Link From north of Wellington ( Buckeye Road ) to Colorado-Wyoming Border 17 miles October 1964

Miscellaneous Interstate 25 Pictures
View of the Colorado Springs skyline as seen from northbound Interstate 25 looking east down Colorado Avenue. Photo taken 11/11/03.
Westbound Lincoln Avenue reaches its junction with Interstate 25 at Exit 193 in Douglas County, south of Denver. Photo taken 08/27/04.
Other Interstate 25/U.S. 87 Pictures
Ramp meters from Colorado 88 onto northbound Interstate 25. Yes indeed, ramp meters have arrived in Denver! Photo taken 02/02/02.
Side view looking east of the Steele Street bridge over Interstate 25/U.S. 87 and the temporary replacement bridge used for pedestrians only. This facility has been replaced with a permanent Steele Street bridge as part of the T-Rex reconstruction project on Interstate 25. Photo taken 02/02/02.
View of temporary pedestrian bridge at Steele Street, looking east. This bridge is gone now that the permanent bridge is back in place. Photo taken 02/02/02.
Many of the older bridges along Interstate 25 have the street name in a small green sign on the bridge so it is visible to traffic passing below. However, while most newer bridges in Colorado do not have similar signage that announce the name of the street passing over the freeway, the new T-Rex bridges have the street names inscribed into the bridges. Photo taken 02/02/02.
This suite of pictures shows the former Steele Street bridge on the day before it was to be demolished overnight by work crews. Photos taken 02/02/02.

Page Updated July 23, 2005.

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