1. The Transcontinental Railroad was completed on December 30, 1868, when the Union Pacific and Central Pacific Railroads were joined together at Promontory Summit in Utah. This event symbolized the unification of the West and East Coast of the United States, enabling travel and commerce across the country to flourish.

2. The Salt Lake City and County Building was dedicated on December 30, 1894. This historic building has housed various government offices and departments throughout the years and is now used primarily for ceremonial events.

3. On December 30, 1918, the deadly Spanish Flu epidemic arrived in Utah. The state was one of the hardest hit in the nation, with over 3,700 reported deaths due to the flu. The pandemic had a profound impact on the state, leading to widespread fear and changes in public health practices.

4. The Utah Jazz played their first game in the state on December 30, 1979, after relocating from New Orleans. The team has since become a beloved part of Utah's culture, with a dedicated fan base known as the "Sixth Man."

5. The Sundance Film Festival began on December 30, 1985, in Park City, Utah. Founded by actor Robert Redford, the festival has grown into one of the most prestigious film festivals in the world, showcasing independent films from around the globe. The festival has also helped to establish Park City as one of the premier ski destinations in the world.