The San Gregorio campsite was a desert camp for the Spanish Commander Juan Bautista de Anza's expedition of 1775 and 1776.

During rain storms the Borrego Sink can turn in to a swallow lake or a vast mud flat.

Coyote Creek is 18 miles (29 km) long and runs from the city of Anza, California to Borrego Sink.

The Coyote Creek riparian zone supports: narrow-leaf willow (Salix exigua), Fremont cottonwood (Populus fremontii), western sycamore (Platanus racemosa), arrowweed (Tessaria sericea), white alder (Alnus rhombifolia), mulefat (Baccharis glutinosa), honey mesquite (Prosopis glandulosa), and tamarisk (Tamarix ramosissima an invasive species).

Coyote Creek riparian zone supports seasonal birds: Bell's vireo, Black-crowned night heron, green-backed heron, common yellowthroat, American kestrel, yellow-breasted chat, black-tailed gnatcatcher, blue grosbeak, downy woodpecker, willow flycatcher, yellow warbler, prairie falcon, red-shouldered hawk, and the black-shouldered kite.