1. On April 20, 1914, a gun battle erupted between rancher Gus Bryson and a posse of Tucson lawmen, resulting in the death of Sheriff Charles A. Shibell. Bryson was eventually captured and sent to prison, where he later died.

2. In 1985, on April 20th, the FBI arrested 12 leaders of the Arizona Republic Militia, a right-wing extremist group that advocated for the overthrow of the government.

3. April 20, 1929, marked the opening day of the Arizona State Fairgrounds, which still operates today and hosts the annual Arizona State Fair.

4. On April 20, 1899, the Arizona Territorial Legislature passed a bill establishing the Arizona Pioneers' Historical Society, which aimed to preserve the history of the region and recognize pioneers who helped shape it.

5. The Sedona International Film Festival, which has become a major cultural event in Arizona, typically takes place in late February or early March, but the 2003 festival was held on April 20th, when it screened the acclaimed documentary "LaLee's Kin: The Legacy of Cotton."