Yawning Penstemon comes in two varieties in Yosemite, one with a glabrous calyx and one with a glandular calyx, which is to say one with smooth flowers and one with hairy flowers. You can see pretty obviously in some of the photos that the ones here are hairy, making them Keckiella breviflora var. breviflora rather than Keckiella breviflora var. glabrisepala. The hairy subspecies is perhaps what gives the species one of its common names: Bush Beardtongue (though Beardtongue is a common name for the Penstemon genus, so it is probably meant that way). It is also known as Yawning Penstemon, Gaping Keckiella and Gaping Pentsemon.
In point of fact, as you can see from the Latin name, it isn't a Penstemon at all, though both genera are in the Snapdragon (or Figwort) family (Scrophulariaceae).
Yawning Penstemon is commonly seen on the south-facing slopes of the north side of Yosemite Valley in the area of Church Bowl, Sunnyside Bench and so forth.