The leaf margins have a markedly 'ciliate' appearance...and, though perhaps subtly, the hairs are mildly 'flattened and membranous-looking' (i.e. 'squamulose', or 'scale-like'). The hairs are also unbranched, which is among the helpful diagnostics for this species...many Draba have branched hairs.

Note also that the corollas are somewhat persistent in this species...and one can still see some shriveled yellowish petals (though blurred & out-of-focus) clinging to fruits along the right edge of the image here.

This keys to species (although with some ambiguity at couplet 13) via the following sequence of leads in the Jepson eFlora Key to Draba:

1': Perennial herb. [Note that there are virtually no annuals at this high of an elevation in the Sierra Nevada.];

8': Basal leaves abaxially hairy. [This can be seen here and in my other 'associated images' in this post, all from the same local population];

13. Plant cushion-forming; flowers yellow; cauline leaves 0. [This choice would seem plausible here...as the tight clustering of small, spherical, basal leaf rosettes of most of the plants in this population could reasonably be interpreted as 'cushion-forming'. But the subsequent species beyond this lead in the key all have stellate leaf-hairs with 2 or more rays, whereas these plants had 'hairs simple'. Note also that the hairs here are somewhat long & squamulose...apropos to the specific epithet longisquamosa.];

13'. Plant not cushion-forming; flowers white (yellow); cauline leaves (0)1–many. [Again, I'd say these look pretty 'cushion-forming'...but perhaps the authors of the key had in mind a tighter, more pronounced notion of 'cushion-forming than I do?];

19' Inflorescence axis hairy. [The term 'inflorescence axis' here is presumably referring to the entire flower scape...not just the portion between the individual flower pedicels];

25. Basal leaves with simple hairs; petals persistent.....D. longisquamosa