California tortoiseshell butterfly or Nymphalis californica
The upper wing surface is orange-brown with large black spots and dark wing borders. The underside is dark mottled brown, darker at the base of the wings; the hindwing does not have a centered silver spot. Wingspan is 1-1/4 to 2-3/4 inches.
California tortoiseshell adults emerge in June and fly until fall, then overwinter to emerge again the following spring. The tattered and worn adults show themselves in April and May, mating and laying eggs for the next brood.
California tortoiseshell butterfly
California tortoiseshell in October
California tortoiseshell caterpillar
feeding on mountain balm