2019 Cranko De Mayo Gravel Grinder 2019 Cranko De Mayo Gravel Grinder Check out highlights from the 2019 Cranko De Mayo Gravel Grinder, a fundraising event put on by the Mad River Riders. Watch the video Check out highlights from the 2019 Cranko De Mayo Gravel Grinder, a fundraising event put on by the Mad River Riders. Previous Article 3,000+ Trout Stocked in Mad River! Next Article Take My Dog Skiing Day