Welcome,thrtypntbck
The black hills are nice.Have seen a few elk while passing through on a couple of trips this year.I have family in Sturgis ,Lead -Deadwood... etc. While the Black Hills are not the Rocky Mntns. You will need to have yourself in shape.I can' t stress that enough!!!!I have generally found that if you don' t find elk in numbers......That you will find cows usually in pairs(2) and that if you can find a meadow (even a small one) between tracts of trees(cover) early in the morning... You could be onto something. I have also found that cows.. in particular will venture towards water especially LATE (last shooting light) in the day.
Took cows last year and last week in just such a meadow and took a cow two years ago drinking at a small pond around last shooting light and have seen many more in the same type of situations many other times.

Good Luck!!