The 10th grader bested a group of professionals aboard her longtime partner, Kensington, at the Langley venue.
New eligibility requirements for foreign participants, including riders, drivers, coaches, etc., will come into effect September 1st.
The 19-year-old Canadian piloted Golden Glock WS to victory under the daunting "Saturday Night Lights" at WEF.
The Canadian shared top honours with Scott Stewart in the 3’6” Green Hunter division during World Championship Hunter Rider Week at WEF.
The Canadian earned both champion aboard Wayland Square and reserve with Epic Style in the Amateur-Owner Hunter 3’6” 36+ division.
The Canadian took the hotly-contested $15,000 USHJA National Open 3’ Hunter Derby at the Winter Classic 7 in Ohio.
A total of 47 sport horses of all ages and stages went through the sale; five were picked up by Canadian buyers.
Campbell-Cooper finished second in both Hunter Derby classes to clinch the title; Tuesday's event was won by Taylor Brooks and Spectre.
“She’s my heart horse for sure,” said Walter of her 12-year-old Canadian Sport Horse mare sired by Cabardino.
Defending champion Kristjan Good piloted Carano to victory; hunter derby action continues on Tuesday evening.