Chaparral pea is endemic to California. It is distributed in the Coast Ranges from the Santa Monica Mountains north to Mendocino County, and in the foothills of the Sierra Nevada from Nevada County north to Butte County. It is also found on Santa Cruz Island. Pickeringia montana ssp. Chaparral pea occurs in mixed chaparral but is not usually dominant.
Chaparral pea is important browse for black-tailed deer.
Chaparral pea browse is rated as excellent to good for black-tailed deer, depending on the season and the number of sprouts available. Fire depletes nitrogen from chaparral soils. Black-tailed deer rarely browse chaparral pea in dense older stands. The fruit is a legume containing 6 to 10 seeds. The primary method of reproduction is vegetative.