The undercard feature on Canada Day was the $250,000 Bison City Stakes, the second leg of the Canadian Triple Tiara, for 3-year-old fillies going 1 1/16 miles on Polytrack. Black Bird Rock was sent off as the 7-5 favorite off her fourth place finish in the Woodbine Oaks
. In to challenge her included 2-1 second choice Blue Heart, a close second in the Alywow last out, and 5-2 third choice Awesome Fire, off a third place finish in the Oaks.
6-1 Casa Loma battled for the lead with 18-1 Simple As That through fractions of 25.45, 49.88, and 1:14.18, while stalked by Blue Heart the whole way. On the turn, Simple As That tired allowing Casa Loma to lead to mid-stretch. Blue Heart rallied late to win by 1 3/4 lengths over late-running Black Bird Rock in 1:45.77. It was just a nose back to pacesetter Casa Loma third.
Results chart from DRF