Howdy Z,
I agree with St. Florian -- rosy boas are my favorite snakes. I've seen and held two in Box Springs. Actually moved them off the trail so no one would hurt them. Saw a rubber boa as we were dropping down to Muir camp in the JMT hike last year.
I've seen gorgeous black pacific diamond back rattler on Deer Springs happily lying on a rock to the left of the trail in the brushy section. We were warned by hikers descending. Good rattler -- we left it alone, it left us alone.
Then there was what looked a Mojave green (hybrid maybe?) on the Fuller Ridge trail that I almost stepped on in 2008

Sucker was lying directly across the trail in the shade of pine trees

Right as I was going to step on it with my right foot (the good ankle), it coiled and rattled. Don't which came first, Karin's scream or the rattle. I did, however, discover that I have selective fast-twitch muscle fibers -- somehow instantly ended five feet back up the trail
The most recent was a really big yellow-ish fellow on Jo Pond.
Miles of smiles,
Ellen