Watertown is nowhere near Sturgis. Was it on your way?
I lived in North Dakota. I owned a Moto Guzzi motorcycle when I moved there. Watertown had the nearest Guzzi dealer, right off I-29. So I went there for major warranty service.
But yes, I also passed through 2 years earlier, on the way to Sturgis, in 1997, on my way back to Seattle where I lived at the time. I'd bought the Guzzi new in Fort Lauderdale on a trip down here. I then rode it home to Seattle solo, stopping at Sturgis.
But I detoured into Watertown, for my first major scheduled service, at a little over 3,000 miles. A lovely married couple owned the dealership, and lived in rooms right above it. While my bike was being serviced his wife washed my clothes in their washer & dryer (I only had what my saddlebags could carry). And we all had pizza delivered for lunch in their kitchen. Talk about hospitality and personalized service!
So when I moved to North Dakota and I wanted to buy a knobby tire dual-sport bike, because of all the dirt farm roads there, I decided to give them my business. They were about 200 miles south of the farming town where I was living. But kinda the way things can be up there, not like in the big city.
I sold the Guzzi, which had gone to Sturgis several more times, and got a Kawasaki sport touring bike. It made the annual August trek to the rally until I moved down to Florida.
Do you know Watertown? It's famous for a native artist celebrity, Terry Redlin. He did some of those snowy Christmas paintings with the twinkly nighttime lighting effects, and other outdoor scenes. The Redlin Art Center, a grand enormous structure, is visible along I-29. Sadly he had to be institutionalized with Alzheimer's, not sure what his status is today.
Redlin Art Center as seen from I-29: