 As part of the Suicide Race, horses and riders run down Suicide Hilla 62-degree slope that runs for to the Okanogan River.Horses must pass a veterinarian examination to ensure they are physically healthy, and a swim test to ensure they can cross the river, to demonstrate their ability to run the race and navigate the river.Several animal rights groups, including Progressive Animal Welfare Society (PAWS), In Defense of Animals and Humane Society of the United States (HSUS), have expressed concerns about the horses' welfare and have opposed the specific event.