Texas Canyon Pass

Texas Canyon is the high point of Interstate 10 in Arizona. The summit, just past the Texas Canyon Rest Area near milepost 320, sits at 4,974 feet, and the westbound lanes briefly cross above 5,000 feet (AARoads; Wikipedia, "Interstate 10 in Arizona"). The road climbs from the San Pedro Valley and Benson up into rocky Texas Canyon, threading between the Little Dragoon Mountains to the north and the Dragoon Mountains to the south, in Cochise County in the southeastern corner of the state.

If you are picturing a snow pass with chain-up areas, set that aside. This is a long, gradual ascent, not a steep mountain grade. Benson sits at about 3,585 feet, so the net rise to the summit is roughly 1,400 feet over about 20 miles east (Benson elevation: elevation.maplogs/DesertUSA; summit: AARoads). No state DOT publishes a grade percentage for it, so do not expect one. Arizona has no chain-control system, and there is no designated chain-up or brake-check area here.

The hazard that actually strands truckers on this part of I-10 is blowing dust, and it hits east of the summit. Between Willcox and the New Mexico line, around San Simon and Bowie, strong winds kick up dust that can drop visibility to nothing. ADOT has closed 60-plus miles of I-10 in both directions during dust events, with detours running 100-plus miles via Safford and Duncan (tucson.com; weather.com). Texas Canyon itself is also a DPS-named serious-crash hot spot, where the road curves past jumbles of boulders at the north end of the Dragoon Mountains.

• Texas Summit is the highest point of I-10 in Arizona at 4,974 feet, just past the Texas Canyon Rest Area near milepost 320; westbound lanes briefly top 5,000 feet (AARoads; Wikipedia, Interstate 10 in Arizona)
• The climb is a long, gradual rise of about 1,400 feet from Benson (~3,585 ft) over roughly 20 miles, not a steep mountain grade (Benson elevation: elevation.maplogs/DesertUSA)
• No state-DOT grade percentage was found for Texas Canyon; Mountain Directory has no entry for it, so no specific grade is published here
• Arizona has no chain-control system and no chain-up law; there is no designated chain-up or brake-check area at Texas Canyon (AZ MVD rules summary)
• The Texas Canyon Rest Area (about MP 320, both directions, ~70 mi east of Tucson) has truck parking covered by ADOT's Truck Parking Availability System, with live counts on AZ511 (ADOT TPAS project page)
• A June 19, 2017 dust storm near Lordsburg, NM caused a 25-vehicle pileup that killed 6 (abc15.com)
• An April 26, 2016 dust event near San Simon closed 62 miles of I-10, with gusts reported near 45 mph (weather.com)

There is no chain-control season at Texas Canyon, because Arizona runs no chain-control system. There are no R-1/R-2/R-3 levels and no chain-up law like California, Colorado, or Oregon. Under Arizona rules, chains of reasonable proportions are allowed when you need traction, and chains or snow tires are only required if ADOT posts a sign for immediate conditions, which happens mainly on northern-Arizona mountain routes (AZ MVD rules summary). The summit itself rarely closes for weather. At about 4,974 feet, a strong winter storm can bring snow and ice on occasion, but no documented pattern of regular winter closures at Texas Canyon was found. The closures that actually shut this stretch of I-10 are dust-storm closures a few miles east, between Willcox and the New Mexico line, and those can come with little warning during high-wind events (AARoads; tucson.com; weather.com). When it happens, ADOT manages it with posted advisories, speed reductions, and closures, not chains. Check AZ511 or call 511 before you run it.

Texas Canyon has been a travel corridor since long before the interstate. The Butterfield Overland Mail stagecoach route ran through the canyon from 1858 until the Civil War interrupted it in 1862 (Wikipedia, "Texas Canyon"). The Dragoon Mountains alongside the canyon held the Apache leader Cochise's final stronghold. In the 1880s, pioneer David A. Adams, who came from Coleman County, Texas, settled the area, and the Texas name reflects those Texas connections and the road heading toward Texas (Wikipedia, "Texas Canyon"; AARoads notes it was "named for being on the road to Texas"). In the 1930s, William Shirley Fulton established the Amerind Foundation, an archaeological and ethnographic research center, library, and museum, near what is now I-10 exit 318.

I-10 came through this corridor in the mid-20th century. The first Arizona I-10 construction funded under the 1956 Federal Aid Highway Act ran from 1957 to 1960, and the Benson bypass opened around 1979, one of the last Arizona sections completed aside from the Phoenix gap (AARoads / interstate-guide construction history). The Texas Canyon Rest Area at milepost 320, about 70 miles east of Tucson, closed for roughly six months and about $3 million in work, then reopened June 30, 2016 (ADOT). ADOT later added a Truck Parking Availability System at the site so drivers can see open spaces.