This critter and I saw each other at about the same time. I said: "Oh!" It said: "Shake that rattle". Or similar. I was a good 15 feet away and in no danger. I backed up to about 40 feet away before it stopped warning me. It was a standoff for a while, but I did kind of want to get to where I was headed so I did an end around.
(Northern Pacific Rattlesnake, Crotalus oreganus)
It looked like it had a foxtail stuck in one of its pits or nostrils.
Side note: while I was getting ready this morning to go out on this walk, I thought to myself, well, you look like a right dork with these snake gaiters on. But, as my husband reminds me, the only dumb safety equipment is the safety equipment you did *not* use and regretted you didn't. So: no regrets today, although technically I didn't need the gaiters because I wasn't very close.