They live pretty much anywhere there's water.
Oftentimes they live on rocky bottomed creeks like where you found him. I have a few orconectes species, and they pretty much adapt to anywhere you put them. Some species live exclusively on pebble bottoms, but virilis is adaptable.
You will need a cave for him, and I'd suggest deep substrate because they like to dig pits. If you put several big pebbles they'll move them around and rearrange them how they like. Anything you put in there that's small enough to move they will essentially use how they want.
One thing I do suggest for ANY native crawdid is some native soft driftwood. All of mine chew on driftwood and sticks periodically and it seems to be a natural, possibly necessary in some way, part of their diet. I didn't know this until I had them, but they all do it, so I provide some for them.
They will also chew on leaf litter, and they should probably have a certain amount of algae in their diet.
Otherwise it's ok to feed them just about anything. Flake food, pieces of meat, small whole dead fish, algae wafers, etc.
They're very hardy.
Oh and another thing. DO NOT REMOVE THEIR MOLT. Crawdads eat their molt to regain the calcium and such needed afterward. They may not eat all of it but you should leave it for at least a few days. Eventually they tend to get through all of it, other than the claws which they sometimes leave.