Beyerstedt has one of only two rounds in the 70s during the first 18 holes at Cedar Valley Golf Course, firing a 3-over 75.
The players then turned around and played nine holes on the “Green Monster” at Cedar Valley. Only one player — Jason Edstrom — broke 40 on the par-36 Monster.
Beyerstedt shot a 9-over 45 on the Monster, yet leads second-place Jason Ewert by four strokes going into today’s final round.
Beyerstedt, Ewert, Zach Erickson and William Leaf will be in the final group at The Bridges Golf Club.
Erickson trails Beyerstedt by nine shots, while Leaf is another shot behind.
Edstrom, who shot 39 on the Monster, is 12 shots off the lead. Edstrom is the defending champion.
The five-day tournament started Monday at St. Charles Golf Course and continued Tuesday at Lewiston Country Club.
It moved into Winona on Wednesday with the third round at Westfield Golf Club.

