We had just started out on the Bunny Flat Trailhead when I spotted this marten streak down a hillside, and make a rush at a Golden Mantled Ground Squirrel. The squirrels all scattered, and we got pretty decent, if sporadic, looks at the Marten as it darted about, before it finally disappeared in a cluster of firs. The animal was too large to be a Long-tailed Weasel, had no white under the chin, and the tail and body proportions all said Marten to me. Pretty well made my whole month, even if the photos are pretty bad.