Small bedrock mortar on the south side of Little Rock Creek, NE of the intersection of Cheseboro and Mt. Emma roads, across the river from the probable location of the Santiago
Garcia adobe in the Tataviam-Kitanemuk boundary area at the edge of the Mojave Desert.
Approximately 2.3 miles north of Little Rock Dam and 8 miles east of the Barrel Springs site
(CA-LAN-82, a Late Period village site with beads dating to 200 B.C. - A.D. 600, which is before and at the time of Tataviam arrival).
Didn't measure, but the diameter of this mortar hole is only about 2.5 inches (6.35 cm); depth no more than 0.5 inches (1.27 cm). It's the large boulder in the foreground of the first photograph below.
LW3189: 9600 dpi jpegs from digital images made February 24, 2018, by Leon Worden.