Great Divide Basin

History

Although the Great Divide Basin provides a relatively low and easy crossing of the Continental Divide, its aridity and endorheic nature were an obstacle to pioneers during the westward expansion of the United States; it was known as the Saline Plain around the 1870s. Consequently, the Oregon Trail detoured north over South Pass, and the Overland Trail detoured south over Bridger Pass. In contrast, during the construction of the first transcontinental railroad, the Union Pacific was laid directly across the southern part of the basin. (The original railroad map labeled one point along this route as Bridgers Pass, giving rise to the still-common misconception that the railroad followed the Overland Trail.) Roughly the same route across the basin was later taken by the transcontinental highways traversing the region, namely the Lincoln Highway, U.S. 30, and Interstate 80. The basin is also traversed in a north–south direction by U.S. 287 and Wyoming 789. Even today the basin is very sparsely populated, the only incorporated town being Wamsutter, with a population of 203 at the 2020 census.

A westward traveler on Interstate 80 crosses from the Gulf of Mexico drainage to the Great Divide Basin at about 41°47′17″N 107°22′34″W / 41.788°N 107.376°W, roughly 7 miles west of Rawlins. A highway sign marks this as a crossing of the Continental Divide, although that is a matter of interpretation. At about 41°42′58″N 107°46′55″W / 41.716°N 107.782°W is the exit for Continental Divide Road, the highest point on I-80 within the Great Divide Basin, at an elevation of 7,130 ft (2,170 m). While this is no longer recognized as a crossing of the Divide, it was evidently considered to be just that during the days of the Lincoln Highway and U.S. 30, and a monument to Henry B. Joy, the first president of the Lincoln Highway Association, was placed just south of this point along the old highway. (It was relocated to Sherman Summit in 2001 to protect it from increasing vandalism.) Further west, I-80 crosses to the Colorado River drainage at about 41°37′52″N 108°18′40″W / 41.631°N 108.311°W. This is now recognized as the true location of the Continental Divide; however, the corresponding highway sign is located at the Tipton interchange, about 2.6 miles to the east at 41°38′02″N 108°15′40″W / 41.634°N 108.261°W, but with a posted elevation appropriate to the correct location. In any case, the placement of the Divide on the west rim of the basin signifies that this otherwise endorheic region would drain to the east if it were to overflow. After leaving the Great Divide Basin behind, I-80 continues west and at 41°16′30″N 110°48′07″W / 41.275°N 110.802°W, around 10 miles (16 km) east of Evanston, enters the vastly larger Great Basin, staying within it until the crest of the Sierra Nevada at Donner Summit.