The Castle Course at Northern Bay is located in the Dells area on the east side of Castle Rock Lake.

The golf course's design features 7 replica holes from notable U.S. golf clubs. The third hole is the par-3 16th hole at Augusta National GC; No. 4 is a replica of the par-4 fifth hole on the South Course at Oakland Hills CC in Detroit; the 525-yard sixth hole is the par-5 16th on the South Course at Firestone CC in Akron, the 10th is the Pete Dye-designed 17th hole at the TPC at Sawgrass, the island green; the 11th hole is the centerpiece of Augusta's Amen Corner, the 13th; No. 12 is the third hole at Oakmont CC with the church pew sand bunker. The balance of the layout is along broad fairways with stands of trees at the margins, a modest amount of sand bunkers, and water hazards in play on five holes overall. It plays to 7,207 yards from the tips, 74/4/131, course/slope ratings with four shorter sets of tees, designed by Matt Mootz.