Very surprised, especially considering the opposite directions the two teams are headed. If I were in Vegas and not a Gopher fan, I'd jump all over the at Badgers +1.
In truth, the Gophers have been decent but not great at home the last couple seasons vs. quality competition (top-50 type opponents). They were 3-3 last season (beat OSU, Illinois & Wisconsin; lost to Sparty, Purdue & Michigan), and they're 1-1 so far this season (beat OSU; lost to Sparty), so maybe that explains the spread.