6 1/16 x 3 15/16 in. albumen stereoview on yellow cardstock mount (light scuff to lower edge; mount corners docked and top edge trimmed). Series title printed to mount recto. Paper labels with image title, subseries, photographer, publisher, and additional information affixed to verso. Red ink inscriptions form a later hand on recto and verso. 

An outdoor group portrait of a large congregation of Native Americans seated and standing among a few trees, bluffs visible in the background. A few white subjects, identified in the title as both Mormons and Gentiles, are included in the crowd. 

John Wesley Powell (1834-1902) and his assistant Almon Harris Thompson (1839-1906) conducted several geographic surveys down the Green and Colorado rivers in Wyoming, and Utah from 1871 through 1874. Though the project was geologic in scope, the researchers had frequent interactions with the local Native Americans captured in these images. Most were taken by John Karl Hillers who was originally hired as a boathand for Powell's second expedition in 1871. He began to assist survey photographers E.O. Beaman and later James Fennemore. By the next season in 1872, Hillers had become the expedition's chief photographer. He continued to explore the West working for the Bureau of Ethnology, the Geological Survey, and the USGS, assembling nearly 23,000 negatives until his retirement in 1900.