A large gathering of Apache at the San Carlos Reservation in Arizona Territory is documented in this albumen stereoview, number 94 in Dudley P. Flanders's "Scenes in Arizona" series, produced during his 1874 expedition through the territory. The yellow mount bears the series title printed vertically on the left border and the photographer's credit on the right, with the caption "Muster Day, at San Carlos Reservation" printed along the bottom edge.

Hundreds of men, women, and children fill the frame from foreground to the distant mountain range, many seated on the open ground in the midday sun. Several figures stand at center wearing wide-brimmed hats and light clothing, while others in the crowd wear traditional headbands and wraps. Makeshift shelters are visible at the right edge, and a handful of non-Native figures, likely military or agency personnel, are visible standing among the crowd.

Flanders visited San Carlos in August 1874, producing a series of images documenting life on the reservation at the moment the Tonto and Yavapai tribes were being relocated there. After returning to Los Angeles, Flanders marketed the photographs under the series title "Scenes in Arizona." The "Muster Day" view, documenting the mandatory military roll call of reservation inhabitants, is among the most historically significant images in the series.

The reverse is blank. A pencil notation at the lower center reads "X A A / 12" and a partial notation at lower left reads "489."