This moss is rare in California and was growing in patches on wet rock, mostly in sheltered recesses but in an open section of the Feather River Canyon, interspersed with patches of with Mielichhoferia elongata.
The moss with very long hair points to the leaves (including the plant with the green capsule) is Crossidium squamiferum. Also present are Bryum argenteum (eg near the top, left of center, and the silvery plants to the right of the Crossidium patch); Aloina sp. (two plants with narrow, dark green leaves with incurved margins towards the upper right) and many plants with triangular yellow green leaves that I'm guessing are a Didymodon species (possibly also a second species with larger leaves).
The photograph was taken at home after the addition of water to a sample collected with a piece of the substrate. This enabled the plants to open to their natural moist state.
This very small 'ephemeral' moss is seen here with a Bryum species. The Acaulon plants are the four bulb-like brown objects near the center of the image, and two more are visible towards and at the bottom right. The plants are probably young since the capsules are still covered by the leaves. The greener moss plants with longer hair points on the leaves are the Bryum species.