A sepia-toned, dome-topped photograph from 1861 captures a coastal landscape looking across a wide, flat plain toward a distant body of water. The foreground is dominated by dark, textured terrain with sparse, low-lying vegetation. In the middle ground, a small, light-colored body of water or salt pond sits in the center of the plain. In the background, a long, low peninsula or point of land extends into the San Francisco Bay, with hills visible on the far horizon under a pale, clear sky. Below the photograph, a wide strip of aged paper is attached, featuring several lines of handwritten cursive text that include "July 24, 1861," "Rancho San Antonio," "100 ND," and "No. 2246." A small color calibration strip with colored and grayscale squares is positioned at the very bottom edge of the mount.