This photo has layers. In the top right corner you see Altadena in the distance. I think of the next layer as the row of sagebrush that lines the path. Then there's the sunny part of the path, then the shady part. Then, in the shaded foreground, see that curved mark like someone took a wide stick and marked the dust? It's the path left by a rattlesnake. You may have to enlarge the picture by clicking on it to see it.
This time of year if you want to hike during the warm times of day you have to watch for snakes. It's just the way things are. They live here and so do we. They watch for us, too, and avoid us just as we avoid them. Case in point: John and I were walking Boz last week when we saw one on the path after it had seen us. The reason we hadn't seen it at first was because it had stopped moving to wait and allow us a wide berth.
What you don't want is the situation where neither you nor the snake is paying attention. Whoa! Surprise! Biting! Excuse me! Ouch! Poison! Sorry, man, I didn't realize it was you. Too late.
I never saw the snake who left this mark on the Sam Merrill Trail. Another hiker told me, breathlessly, that she'd seen it go into the underbrush. She was afraid it would turn around and come back. But I'm pretty sure once that snake got wind of us, he wasn't coming out until until every last hiker was long gone.
(This one's for AmyR.)