1. On December 20, 1848, the first mail service was established in Utah when Samuel Hensley received a contract from the U.S. government to deliver the mail from Fort Kearny to Salt Lake City. This was a significant development for the growing settlement, as it allowed for better communication and faster delivery of news and mail.

2. December 20, 1875 is the birthday of Esther Hobart Morris, who was the first female Justice of the Peace in the United States. Although Morris was not from Utah, her historic achievement paved the way for women's rights and gender equality in the state and across the nation.

3. In 1892, Brigham Young Academy (now Brigham Young University) played their first basketball game on December 20, defeating the Provo YMCA by a score of 6-2. This marked the beginning of a long and successful athletic tradition for BYU, which has since become one of Utah's premier universities.

4. December 20, 1938 saw the dedication of the gorgeous Tabernacle Choir Organ in Salt Lake City's historic Tabernacle building. The organ was built by the world-renowned Kimball Organ Company, and it remains one of the largest and most famous musical instruments in the world.

5. December 20, 1985 was a significant day in Utah's history, as it marked the opening of the Salt Palace Convention Center in Salt Lake City. The massive complex was designed to attract huge events and conventions, and it has since become a major economic driver for the entire state. Today, the Salt Palace remains one of Utah's most iconic landmarks and a symbol of its bright future.