1. On June 20, 1998, the Arizona Cardinals played their first game in their new stadium, Bank One Ballpark (now Chase Field), which was built in downtown Phoenix. The stadium is known for its retractable roof and unique architecture.

2. In 1864, the Battle of Picacho Pass took place on June 20, between Confederate and Union forces during the American Civil War. Although it was a small skirmish, it marked the westernmost battle of the Civil War.

3. On June 20, 1930, Arizona’s first state highway system was established by the Arizona Highway Department. The system consisted of numbered highways, with the first being U.S. Route 80, which ran east-west across the state.

4. The Phoenix Zoo, which opened on November 21, 1962, was formally dedicated on June 20, 1962. The zoo is home to over 1,400 animals and is known for its conservation efforts and educational programs.

5. On June 20, 1917, the first experimental radio broadcast in Arizona took place from the top of the Hotel Adams in downtown Phoenix. The broadcast was made by Arizona's first licensed radio station, KFAD, which went on the air later that year.