The outlaw trails were a series of escape routes and trails. They were usually in areas that were unfamiliar and not safe for the law to pursue. Men who were trying to escape the law used these trails. The group that used the trail most often wanted to be known as "The Train Robbers' Syndicate" but got the nickname "Wild Bunch." It was set up by Butch Cassidy, and ran from Canada to Mexico. They had it set up so that every 15 miles there would be a place where fresh horses and supplies could be purchased as needed. These places were normally ranches. The Big Muddy was the first station on the trail. The trail wound Southward to Miles City, Montana then to Deadwood, South Dakota through the Black Hills County to Hole in the Wall, Wyoming and on to Brown's Park. It then crossed over Diamond Mountain and through an Indian reservation to Robbers' Roost, Utah. After going through Arizona they went on to Wilson Ranch in New Mexico, then across the border to safety in Ciudad Juarez in Old Mexico. Sundance Kid, a member from the "Wild Bunch" group, was in the Big Muddy area many times.

After the Indians occupied the area and before the settlement, there was a period of outlaw history. The US had developed west more quickly than Canada, but its law structure was not organized. The outlaws sought protection in the Big Muddy. Here there were lots of canyons and gulches to hide in. They would sell their horses to a homesteader and steal the horseback later on. They would then move on to the next innocent homesteader and continue to rob them. Branding didn't help very much at all because they could be changed or unregistered so it was tough to keep straight. The outlaws were so successful because they were able to make friends with ranchers and other people. They were able to find out important information. The ranchers would give pasture for the horses and sell supplies. They rarely told anyone about what they were doing so it was rare that the law would know who was helping and who was not.

There was a North West Mountain Police detachment at Wood Mountain but the patrols were too far away to police the area so they made a post at the Big Muddy. Because of prohibition in Saskatchewan, small gangs developed and carried on so the need of the Big Muddy post stayed around till about 1930. Cassidy usually made a clean get away. Henry Yeuch, alias Dutch Henry, was a horse thief but a very good cowboy. He ran horses back and forth along the border. He'd threaten ranchers constantly and the ranchers would conform to his demands. Nelson, alias Sam Kelly, gave himself up to American authorities in Plentywood, Montana. The crimes he committed were tough to prove so he was only charged with helping a prisoner escape. Nelson took up ranching in 1913. He was thought to have been the ringleader of a few gangs. Kelly left the Big Muddy area about 1914 and went to Debden SK, everyone thought he was a normal homesteader. They might have had Butch Cassidy and the Sundance Kid in the area but it's hard to know because they were so sneaky.