The part of I-25 in Colorado passes just east of the Front Range of the Rocky Mountains. That stretch was involved in a large-scale renovation named the Transportation Expansion (T-REX) Project[3] in Denver and the Colorado Springs Metropolitan Interstate Expansion (COSMIX).[4] These projects, and others in New Mexico, were necessary because these stretches of I-25 were originally inadequately designed and constructed (the pavement was deteriorating rapidly) and also because urban areas, like Albuquerque, Colorado Springs, and Denver, had tripled and quadrupled in population much earlier than anyone had anticipated back in the 1950s and 1960s. Major highway work for the T-REX project ended on August 22, 2006. The COSMIX project was completed in December 2007. Several other smaller improvement projects for I-25 are still ongoing within New Mexico and Colorado.
As I-25 nears Albuquerque, it has interchanges with highways, such as US 380, and a concurrency with US 60.[9] Further north, State Road 6 (NM 6), former US 66, meets up with I-25 in Los Lunas.[10] Through Albuquerque, I-25 is named the Pan American Freeway, and there are frequent exits to city streets.[11][12]: 248 A major interchange with I-40 (which is styled as the Coronado Freeway in the city) is named the Big I.[12]: 248 [13] It was given an honorable mention by the US Department of Transportation and the Federal Highway Administration for excellence in urban highway design in 2002.[14]
Leaving Albuquerque to the north, I-25 curves to the northeast as it approaches Santa Fe.[15] Continuing 'northbound' at Santa Fe, I-25 heads southeast for approximately 45 miles (72 km) traveling through the Santa Fe National Forest and crossing Glorieta Pass (elevation 7,452 ft or 2,271 m).[16] It turns north again at Blanchard toward Las Vegas.[17] The highway maintains a north and northeast orientation as it leaves New Mexico traversing Raton Pass (7,798 ft or 2,377 m[18]) and enters Colorado. Due to its elevation and frequent winter snowstorms, I-25 is sometimes impassible and closed in both directions at Raton Pass during winter months. From Santa Fe to Trinidad, Colorado, I-25 approximates part of the route of the Santa Fe Trail.[19] For its entire length in the state, I-25 shares its alignment with US 85, although the latter is unsigned.
I-25 has many nicknames through the state's larger cities. In Denver, it is called the Valley Highway, as the highway parallels the course of the South Platte River throughout the downtown area and is often sunken below ground level. The section in El Paso County is named the Ronald Reagan Highway, and, through Pueblo, it is named the John F. Kennedy Memorial Highway.
In the Federal-Aid Highway Act of 1973, a transcontinental highway was named after President Dwight D. Eisenhower, in commemoration of the route of the US Army's 1919 convoy. This route, rather than following a single highway, spans several, including I-25 in Denver. This combination of routes was intended to approximate the original 1919 convoy route.[20]
The designation of this highway, while clear in intent, has not seen widespread adoption in terms of signage or recognition, likely due to the irregular nature of the route. Despite this, a commemorative sign was installed in 1986 in the tourist information center off I-70 in Kansas City, Kansas.[21] Congress attempted to honor Eisenhower's contributions to the Interstate System once more in 1990, leading to the renaming of the Interstate System as the "Dwight D. Eisenhower System of Interstate and Defense Highways".[22]
I-25 enters Colorado 14 miles (23 km) south of the city of Trinidad. It is the main north–south route through Colorado with a length of 300 miles (480 km). The Interstate exits Colorado in the north about eight miles (13 km) south of Cheyenne, Wyoming. I-25 serves all the major cities in Colorado that are east of the Rocky Mountains, such as Denver, Colorado Springs, Pueblo, Fort Collins, and Greeley. For the entire distance in Colorado, from the north to the south, the Rocky Mountains are clearly visible.
I-25 crosses the Palmer Divide between Denver and Colorado Springs, providing some of the highway's most scenic views of the Rocky Mountains and its foothills. Blizzards and high winds on this stretch (particularly over Monument Hill) are notorious for causing traffic problems during the winter months.
The section of I-25 that is between the northern border of Pueblo County and the New Mexico state line is named the "John F. Kennedy Memorial Highway" in honor of President Kennedy's support of water resources development in the Arkansas River Valley.
I-25 enters Wyoming eight miles (13 km) south of the state capital, Cheyenne. After traveling through Cheyenne, I-25 continues north to Douglas, passing many plateaus and also railroad tracks. Commonly, very long trains can be seen slowly moving alongside this highway. Around Douglas, this Interstate Highway curves somewhat to the west toward Casper. Once through Casper, I-25 turns due north, and it goes as far as Buffalo, where it ends at an interchange with I-90. I-90 then provides the connection to Montana.
History
The section in New Mexico between Romeroville and Los Lunas closely follows the original alignment of US 66, which was later shortened and realigned to run due west from Santa Rosa. Now, that has been replaced with I-40.
US 85 in Cheyenne. The highways travel concurrently to Ranchettes.
US 26 west-southwest of Dwyer Junction. The highways travel concurrently to southeast of Glenrock.
US 18 / US 20 in Orin. I-25/US 20 travels concurrently to southeast of Glenrock.
US 20 / US 26 / US 87 in Casper. I-25/US 20/US 26 travels concurrently to the Casper–Bar Nunn city line. I-25/US 87 travels concurrently to north-northeast of Buffalo.
^Google (July 7, 2007). "I-25 nearing Santa Fe" (Map). Google Maps. Google. Retrieved July 7, 2007.
^"Glorieta Pass". Santa Fe Trail National Scenic Byway. Santa Fe Trail Scenic Byway Profile. Archived from the original on December 6, 2013. Retrieved February 13, 2013.
^Google (July 7, 2007). "I-25 near Las Vegas" (Map). Google Maps. Google. Retrieved July 7, 2007.
^"Raton Pass". National Historic Landmark summary listing. National Park Service. Archived from the original on June 6, 2011. Retrieved October 13, 2007.
I-10 / US 85 / US 180 near Las Cruces, NM
I-90 / US 87 in Buffalo, WY
