MN rest areas are restricted to a 4 hour parking limit unless otherwise posted. If you're commercial then that limit is 10 hours. Thompson Hill is designated as a "rest area".
On almost night, you will find 15-20 cars overnight here, and since the Minnesota State Patrol has an office on the end of the parking lot, I'm going to assume overnights are ok, as long as you behave yourself. I've overnighted here quite a few times, and have never once been questioned...
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