Nothing will get your blood going like all of a sudden realizing youre standing right on top of a venomous snake. I have a very similar story:
Back when I bought my house out in the country I was single and making less money, so to mow my ~2.5 acre yard at the time I bought a push mower. It sucked but its all I could afford at the time, and I was 28 years old and excited about my property and ready to take on the work. It took me like 5-6 hours of pushing on a Saturday to mow all the grass. I was also cutting down various trees in the yard that I could drop in a safe spot. The yard was overgrown and was way too woody so I was doing lots of weekend projects to slowly transform the property. One saturday I was mowing, I was getting near the end so I was tired and ready to be done. I mowed past the stump of an oak tree I had cut down some time prior - it had already begun to sprout back out from the stump so it had a little bush around the stump of new growth. I walked past that little bushy stump about 3 or 4 times making my passes. This is in the middle of my yard this stump. On the last pass I kinda pushed the mower a little into the bush as I went past to cut the grass close. The blade of the mower caught the tale of a 4 foot timber rattler that was coiled up under there and he immediately thrashed around. I remember just out of the bottom of my vision seeing something big flop out and I look down and saw the pattern on his back. He flopped out right in my walking path behind the mower I was pushing. One more step and I would have stepped on top of him. My eyes caught the pattern on his back and with cat like reflexes I remember just pushing the mower and jumping about 10 feet back. I was a bit shaky for a few minutes because I knew I had walked and brushed up against those sprouts about 4 times already. He had been laying in there just inches from me as I walked by multiple times.
After the initial event, he slowly began slithering away. I decided however to kill him because he was in my yard, 50 feet from my front door and I had also inflicted a nasty wound on his tail with the lawn mower. His rattle was completely missing. I got my little ruger 10/22 and shot him. For a Timber rattlesnake he was a big guy - over 4 foot long and as thick as your forearm. Timber rattlesnakes don't get as long as diamond backs. The predominant rattle snake around my parts is the timber rattler. Since this encounter I have seen numerous other rattlesnakes on the property, and all of them have been timber rattlers. I tend to see one every year on average around our property. Once I came across a little baby in the yard, so I know there had to be a nest somewhere very close. Anyways thats my little story.