Common. Blooms all year.
For a long time I confused this with California Chicory. While the flowers look very similar from the top, from the side they are completely different with the involucres much shorter in this species. The plant itself also looks different, this species usually has a tangle of woody branches while the chicory has a single stem and is an annual. This species has a profusion of simple leaves while the chicory has a few widely-lobed leaves generally near the base. In the front country, Cliff Asters are far more common than this chicory, but I’m not sure I’ve ever seen a Cliff Aster in the back country (and I have seen California Chicory there).
This species has several sub-species of which the nominate sub-species (Seaside Daisy) is the most distinctive with much larger flowers. Seaside daisy, as its name suggests, is found on ocean bluffs, while cliff-aster is found up on the trails.