Pholisora catullus
Common Sootywing
This small skipper is in most counties in southern California, but it is not common in my experience. There are few records on iNaturalist as well for southern California. Generally, these lack submarginal white dots on the hind wing, or they are very small, especially compared to those considered crestar in the Sherman Pass vicinity. Catullus may be single or double-brooded, depending on conditions. The caterpillar food plants are various Amaranths and goosefoots, including natives Amaranthus fimbriatus (Amaranthaceae) and Chenopodium californicum (Chenopodiaceae). They may also be found using non-native Chenopodium murale, and I've seen an egg at Cactus Spring Trail that I believe to be this species on Salsola tragus (Russian thistle), which is also in the Chenopodiaceae, or goosefoot family. Unfortunately it didn't hatch.