UTAH:
General Description.—Nelson and Madsen (1987): Associated with the rise and fall of Lake Bonneville. As summarized by them, the Stansbury level of about 1,372 m was reached at about 23,000 BP and remained at this level for ca. 3,000 years; then the lake rose farther to 1,551 m (Bonneville shoreline) and began to overflow thru the Zenda threshold (N of Red Rock Pass, ID) ca. 16,000 BP; fluctuated near this level for ca. 1,000 years and then the "dam" gave way, leading to catastrophic flooding in the Snake River Canyon. Lake was lowered ca. 107 m where it stabilized at Provo Shoreline (1,445 ,) with outlet at Red Rock Pass. At ca. 14,000 BP, began substantial and rapid decline to ca. 1,274 m by 11,500 BP. Resurgence to ca. 1,295 m, culminating at ca. 10,500 BP. Then decline to historic levels; historic high in 1986 at nearly 1,284 m).
Age.—Nelson and Madsen (1987) point out that the Bonneville fauna is, then, less than 30,000 years old, with the majority of specimens from between 23,000 and 11,000 BP. They list (p. 321) 39 localities.
Publications.—Harris 1985; Nelson and Madsen 1983, 1987.
Faunas.—
Last Update: 21 August 1998.