The last time that I jumped was about ten years ago. It was a spectacular jump.
My property straddles a boundary of short grass prairie and sagebrush desert. I took my dogs out for a romp. They were running through the prairie while I was walking along a path just outside of the sagebrush. I was watching them since this area isn't fenced. Then I looked down and saw that there was a snake with big blotches under my foot. The next thing that I recall was standing about three feet away. The jump was subconscious.
Then I thought, "I wonder if that is a rattlesnake." The snake was poised to strike although he or she was too far away. I saw the triangular head and the depression in front of the eyes; I thought: "Yes, that is a rattlesnake." The snake then turned and crawled into the sagebrush. There wasn't much of the rattles left; I had apparently stepped on them.
I didn't know whether there were bull snakes in my area at that time. They're harmless, but they could be mistaken for rattlers with only a quick glance. There are no bull snakes here, just rattlesnakes and an occasional garter snake.
My dog gets a snake shot every year, My other dog was bitten once, but, having been vaccinated, he had an easy recovery.
That was the most memorable jump of my life.