A rare and endemic wildflower, the Walker Pass milkvetch (Astragalus ertterae) of the pea family, grows within the Pinyon-Juniper woodland. It grows in the sandy-loamy to granitic soils associated with pinyon pines and canyon live oaks. It is primarily found on west-facing slopes from elevation. The Walker Pass milkvetch was first described in 1987 from a collection made in 1982 along a newly constructed section of the Pacific Crest Trail. There are fewer than 10 populations of this perennial herb, all of which are located in Kern County. Very little information is known about this plant, nor is it listed under state or federal endangered species laws. If this plant truly is as rare as presently believed, it is crucial that all existing populations be protected. said M. Elvin of the Bureau of Land Management.