I've been to Sturgis several times, just not during the big week. They have a great motorcycle museum there. However, we passed through the Black Hills once on vacation during the rally week, but stayed away from Sturgis but there were sill bikers all over the place.
Here's a couple of pictures of the museum I took on one of our photo safaris with my old school/Army buddy Dennis (the ex-CIA guy), who died earlier this year. Note that we had already put a plan together, complete with proposed stops and overnights identified, with estimated daily driving distances and everything, for next April (2021) when we were going to explore the Southwest states.

October 2009 (Sony A100)

October 2009 (Sony A100)