William C. (Outlaw Bill) Moore lived and worked on both sides of the law. No one seemed to know his date and place of origin, but according to Charles A. Siringo, Moore's long flight from the law began in California, where he shot and killed his brother-in-law. After making his way to Cheyenne, Wyoming, he became range foreman of the Swan Cattle Company. By summer 1877, however, he was again on the run after killing his black coachman. In the fall of 1877 Moore arrived at the LX Ranch in the Texas Panhandle on a worn-out pony and asked for work. Adhering to the ranchers' unwritten rule of not prying into a man's past, the LX owners, W. H. Bates and David T. Beals, promptly took him on and shortly afterward made him manager. Siringo, who was also working at the time for the LX, declared that Moore was "a natural leader of men" who "could get more work out of a gang of cowboys" than anyone on the range. He quickly won the respect of the hands, and his knowledge of Spanish and certain Indian languages proved a valuable asset. He organized the nine-man posse that recovered, without bloodshed, the merchandise and stock stolen from Pitcher's store by Mexican thieves in December 1877 and was in charge when the LX joined other free-range outfits in the Panhandle's first big cooperative roundup in April 1878.
Although he proved himself a capable foreman with unusual roping and riding abilities, Moore also began rustling LX cattle to feather his own nest. With two cowboy associates, he established his own ranch at Coldwater Springs in the Panhandle of Oklahoma, then known as No-Man's Land. Nevertheless, he maintained the LX men's loyalty and continued in his management position until August 1, 1881. At that time he resigned under increasing suspicion and sold his Coldwater Springs holdings to the Prairie Cattle Company for $70,000. With this money Moore established a new ranch in the American Valley of western New Mexico. But his stay there was apparently brief, for he was soon running again from the law with a price on his head after killing two more men. At that point Outlaw Bill's trail seemingly vanished. Some years later Siringo, by then a private detective, reportedly came across a letter written in Moore's peculiar handwriting. Later, while trailing gold thieves in Juneau, Alaska, Siringo chanced to meet a tall, gray-eyed trapper on the street. Although the man denied that he had ever been in Texas, much less on the LX, Siringo was convinced that he was Moore going under an assumed name. Siringo learned that this trapper came to town only once a year from his mountain retreat. Moore was never heard from again, but Siringo and other former LX employees declared that "if a person ever saw him once, he would know him the next time anywhere."