William Brocius (1845 – March 24, 1882), better known as Curly Bill Brocius, was a gunman, rustler and an outlaw Cowboy in the Cochise County area of the Arizona Territory during the early 1880s. His name is likely an alias or nickname, and some evidence links him to another outlaw named William "Curly Bill" Bresnaham, who was convicted of an 1878 attempted robbery and murder in El Paso, Texas. Brocius had a number of conflicts with the lawmen of the Earp family, and he was named as one of the individuals who participated in Morgan Earp's assassination. Deputy U.S. Marshal Wyatt Earp and a group of deputies including his brother Warren Earp pursued those they believed responsible for Morgan's death. The Earp posse unexpectedly encountered Curly Bill and other Cowboys on March 24, 1882, at Iron Springs (present day Mescal Springs). Wyatt killed Curly Bill during the shootout. In his journal written in October 1881, George Parsons referred to Brocius as "Arizona's most famous outlaw".