Generally, in the midwest and northeast the only venomous snakes are rattlesnakes. They seem to generally stay away from areas where there are people. So, when I do trail hiking I don't usually worry about snakes.
When you go off-trail, there is a concern with the grasses hiding snakes. However, snakebites are a rare event here.
I looked up South Dakota snakes, and it turns out that the prairie rattlesnake only lives in open prairie land. So, I doubt they would live at the higher elevations in the Black Hills.
"Got tight last night on absinthe and did knife tricks. Great success shooting the knife into the piano. The woodworms are so bad and eat hell out of all furniture that you can always claim the woodworms did it."