The fourth place continues the strong season being enjoyed by Brockhoff, who placed seventh 10 days ago at the World Championships in Kreischberg, Austria.
American Lindsey Jacobellis was first, with Canada’s Dominique Maltais second and Frenchwoman Nelly Moenne Loccoz in third place.
Fellow OWIA/NSWIS athletes Cam Bolton and Jarryd Hughes made it through to the quarter finals in Aspen, with both athletes being eliminated from the event after finishing their heats in sixth place.