On event days, there should be signs placed from downtown Red Wing to get you to the hill - otherwise, here's one way to get there:
From Highway 61, turn south (away from the river) on West Ave.

Follow West Ave. to Seventh (7th) St. - then turn left on Seventh.

You'll just go to the next intersection, then turn right on East Ave.

Follow East Ave. to Twelfth (12th) St. - turn right on Twelfth.

Follow Twelfth St. to Seymour St. - turn right on Seymour.

From Seymour St, turn left on Chestnut St.

Finally, from Chestnut St. turn left onto Bohmbach Dr., which is right by the city athletic fields and a church.  Bohmbach will lead you right into our gates.

Note that when leaving, obviously you just reverse these directions, but don't turn off of East Ave. - East Ave. will run straight to 61 (portions of East and West Avenues are one-way).
For an interactive map, try this one from Mapquest.