Seen here on a flower of Anisocoma acaulis in sandy desert scrub habitat.

I believe the very well-defined, white pubescent grooves along the inner edges of the eyes are a (more conspicuous than usual?) instance of what is referred to as "facial foveae", which are diagnostic of Andrenidae and Colletidae (see item "3" in table of family characters on page 44 of Stephen, Bohart, & Torchio(1)).

Neither the mid, nor posterior, portions of second recurrent vein appear especially outwardly arcuate to me, which suggests Andrenidae rather than Colletidae (per item "12" in the aforementioned table(1)). The conspicuously dense pilosity of the face and shape of the marginal cell at its apex suggest subfamily Andreninae...and what appears to be two submarginal cells here would then significantly narrow choices within Andrena (most of whose species have 3 submarginals).

Perhaps this is something in Diandrena (the "two-celled Andrena")? Maybe, Diandrena olivacea? The second sentence in the excerpt for Diandrena olivacea here from Robbin Thorp's 1969 treatment of subgenus Diandrena states that:

"Andrena olivacea is the only species of the subgenus which occurs primarily in the desert areas."