Yosemite and Tioga Pass Area

Arrowleaf Groundsel (Senecio triangularis) has few to numerous yellow flower heads in a small cluster at the top. The head includes 8 ray flowers toothed at tips and 40 disk flowers in center. It grows in wet meadows, conifer forests and streambanks, at mid to alpine elevations. The description fits, but there are many other yellow composites it could be.