Isabel Pass

Isabel Pass (sometimes Delta River Pass) is a 40 mile long gap in the eastern section of the Alaska Range which serves as a corridor for the Richardson Highway about 11 miles from Paxson. It is named after the wife of E. T. Barnette, who helped found Fairbanks. The pass separates four regions, the Tanana Valley to the north, the Delta Mountains to the east, Copper River Basin to the south, and the Hayes Range to the west.

It is one of three highway passes of the Alaska Range, the others being Broad Pass for the George Parks Highway and Mentasta Pass for the  Tok Cut-Off.

History
Various Dena groups have inhabited the surrounding areas for thousands of years. Indigenous place names describing land features formed by ice that no longer exist suggest that they have been living in the area since at least the last ice age.

The first recorded non-natives to cross the pass was a military expedition in 1898 led by Edwin Glenn, along with  Walter Mendenhall, who was a geologist attached to the expedition. They turned around 15 to 20 miles short the Tanana River due short supplies and lateness of the season.

The founding of Fairbanks in 1901 began non-native interest in Isabel Pass. Sometime in the spring of 1902, E.T. and Isabelle Barnette crossed the pass on their way to Valdez and onto Puget Sound to purchase supplies for the newly formed city. The pass was then named after Isabelle, although it was spelled incorrectly. Later that year, gold was discovered in Fairbanks, which drew attention away from the Klondike Gold Rush. This resulted in the establishment of the Valdez-Fairbanks Trail, an offshoot of the earlier Valdez-Eagle Trail. The early trail followed the Valdez-Eagle Trail, then split at the Gakona River, then crossed Isabel Pass and the Tanana Valley. Under the supervision of Wilds P. Richardson, an all-season wagon road was completed in 1910 from Valdez to Fairbanks. The first recorded automobile to go through the pass was in 1913 driven by Bobby Sheldon and three passengers. The wagon trail later became the Richardson Highway, the first long-distance road in Alaska.

The pass came under the soil and water conservation of the Salcha-Big Delta Soil and Water Sub-District in 1950, known today as the Salcha-Delta Soil and Water Conservation District. The highway going through the pass remained gravel until it was paved in 1955 and provided year round travel. The Northern Warfare Training Center was established at Black Rapids in 1956, near the middle of the Isabel Pass.

In the late 1970s, the Trans-Alaska Pipeline was built through the pass. The camp situated at Isabel Pass was also the largest during pipeline construction, with 1,652 beds.

The 2002 Denali earthquake struck the region. Soil liquefaction, sand blows, and subsidence caused some damage in the immediate area.

Geography
It is one of the drainage divides of the Alaska Range. To the north, is the Yukon River drainage that flows into the Bering Sea, and to the south is the Copper River drainage that flows into the Pacific Ocean. The Denali Fault approximately bisects the pass, near Miller Creek, just south of Canwell Glacier. Castner Glacier is located on its southern end.