Ipomopsis aggregata.   Synonym: Gilia aggregata. (Scarlet Gilia)
Polemoniaceae (Phlox Family)

Semi-desert, foothills, montane. Woodlands, meadows, openings. Spring, summer, fall.
Horse Creek Trail, July 18, 2007.

These are the only yellow Ipomopsis aggregata I have ever seen (or heard of!).