The spores on these ( approx. 6.8-8.2 X 4.5-5.7 microns) do fall into the right range for C. cinnamomeus or C. croceus but the coloring doesn't quite seem to fit nor the habitat. They were growing in a grassy area with only a live Oak and a Madrone nearby. At the suggestion of Irene and Dimitar, I've changed the name to Cortinarius croceus to reflect what these more closely resemble.