Key notes: The Structural Buildings WISSOTA Challenge Series concludes its five-race weekend with Sunday’s 40-lap, $3,000-to-win Labor Day Shootout finale. … Two two-day program began when Joel Bennett of Hortonville, Wis., led the final 18 laps of Saturday’s $3,000 Shootout opener for his first career Challenge Series victory. … Shane Sabraski of Rice, Minn., has won two of the last three Challenge Series rounds, earning Thursday’s $4,000 Silver 1000 at Proctor (Minn.) Speedway before Friday’s $3,000 WISSOTA Classic at Grand Rapids (Minn.) Speedway. Sabraski topped 2024’s Tom Waseleski Memorial at Hibbing, worth $11,111. … Kyle Peterlin has eight career Hibbing specials at his home track, including six on the Challenge Series, worth more than $24,000. … Darrell Nelson of Hermantown, Minn., has three major wins in the last five years there, collecting more than $11,500. … Skeeter Estey of Kelley Lake, Minn., picked up a $3,000 WISSOTA Late Model victory in July. … Johnny Broking of Grand Rapids, Minn., topped a WISSOTA Late Model field in July 2024, worth $5,000. … Modifieds, super stocks, midwest mods, hornets, Crown Vics, mini stocks and mod 4s are on the undercard. … Pits open at 1 p.m. and grandstands open at 2 with racing at 5. … Watch live on Dirt Race Central.

Who to watch: Shane Sabraski of Rice, Minn., seeks his third Challenge Series victory of the five-race Labor Day weekend.

Points chase: Before Hibbing Sunday: 1. Kevin Burdick (708); 2. Shane Sabraski (686); 3. Dave Mass (649); 4. Jeff Provinzino (610); 5. Johnny Broking (609).

Expected entrants: Shane Sabraski, Kyle Peterlin, Kevin Burdick, Dave Mass, Darrell Nelson, Jeff Massingill, Johnny Broking, Joel Bennett, Jeff Provinzino, Ryan Mikkelson, Cory Crapser, Skeeter Estey, Gunner Frank, Adam Ayotte, Keith Niemi, T.J. Heinle, Jayme Lautigar, Derek Vesel, Kevin Carlson, Ben Heinle, Dexton Koch, Taylor Madrinich, Zach Wohlers and others.

Next series race: September 15, I-94 EMR Speedway (Fergus Falls, MN) $3,000