The Zoomies 50K also offers a 5K, 10K & 15K option. The race goes around a 1.57-mile loop so you complete it 20 times for the 50K. Dogs are welcome and the course will feature rescue animals available for adoption.
The Salt Flats Endurance Run in an ultramarathon that allows dogs in all distances, including the 50K, 50 miler and 100 miler. You can register your dog to run the entire race and they will essentially be treated as a human runner.