Vol. IX] TAYLOR— COOPER'S MAMMALS 75 



ward to Panama en route to New York; and he evidently 

 remained in the east until the spring of 1857 (Suckley and 

 Cooper, 1860, p. x). During these early explorations Cooper 

 had spent six weeks in California and approximately two 

 years and three months in Washington Territory. 



On April 22, 1857, Dr. Cooper was appointed surgeon to 

 the South Pass Wagon Road Expedition. The party of 

 William M. Magraw, the Superintendent of the expedition to 

 which Dr. Cooper was attached, left Independence, Missouri, 

 about July 1 (See Campbell, 1859, pp. 5, 6), reaching the 

 headwaters of Sweetwater River late in September, "too late 

 to proceed with safety through the South Pass and into the 

 Wasatch Range, in consequence of the severity of the winter 

 in that region and the hostile attitude of the inhabitants of 

 Utah toward the authorities of the United States at this 

 time." In consequence of these considerations the party was 

 disbanded on "Popo Agie, a tributary of Wind River." Some 

 members of the expedition returned to the frontier, others 

 accompanied the chief engineer, Mr. F. W, Lander, to Wash- 

 ington, a few were left on the Popo Agie River in charge of 

 the public property, and a large number volunteered into the 

 service of the army of Utah, selecting their superintendent as 

 their captain. From records^ of specimens collected by Dr. 

 Cooper we learn that movements of the expedition were ap- 

 proximately as follows : The greater part of May and June 

 was spent at Independence, Missouri, records of specimens 

 collected at this point embracing the period between May 6 

 and June 30 ; July found the party moving in a general north- 

 westerly direction toward Fort Kearney, Nebraska ; Fort Lara- 

 mie [Wyoming], the most westerly point reached by Cooper 

 (see Suckley and Cooper, 1860, p. xi), was reached the latter 

 part of August, the first specimens having been collected at 

 this locality on August 27; the diminished expedition had not 

 started on the return journey before October 5 (Baird, 1858, 

 p. 322), but must have moved soon thereafter, for October 

 10 found the party at a point 100 miles east of Laramie; 

 October 19, 40 miles west of Fort Kearney; October 28, 100 

 miles east of Fort Kearney; and November 5, 50 miles west 

 of Leavenworth. 



• In the mammal catalogs, U. S. National Museum; in Baird's Mammals of North 

 America, 18S7; and Birds of North America, 1858. 



