"A double peaked lava cone formation, Bill Williams Mountain appears on the map made for the Sitgreaves' survey by Richard H. Kern in 1851. In Arizona during the year 1837, Antoine Leroux, a famous guide, met the rugged "mountain man" after whom the mountain is named. At that time William's was in Arizona alone on the river which now bears his name. He had traveled through the Mogollon and Little Colorado River region, living off the land and trapping beaver. Leroux reports that Williams headed north across the Colorado River, thus completing his only known visit to what is now Arizona.

William Sherely Williams served as an itinerant preacher for nine years, followed by twelve on the frontier and an additional seven as a plains man and mountain man, according to Zebulon Pike, who knew him. Pike described Williams as a hunter and trapper who was tall, gaunt, redheaded, and said he was fairly well educated. While transporting baggage for the Fremont expedition, Williams was killed by Ute Indians in 1849. Two years later Kern used information given by Antoine Leroux in placing the name of Bill Williams on a Mountain and river in Arizona."