1. In 1858, gold was discovered in the Rocky Mountains of Colorado, sparking the Pikes Peak Gold Rush.

2. On June 28, 1881, the infamous gunfight at the OK Corral took place in Tombstone, Arizona, involving Wyatt Earp, his brothers, and Doc Holliday, all of whom had ties to Colorado.

3. Colorado became the first state in the U.S. to legalize recreational marijuana on June 28, 2012, making it a hot spot for cannabis tourism.

4. June 28, 1971 marked the opening of the first section of the Mesa Verde National Park and its famous ancient cliff dwellings, showcasing the rich cultural history of the region's Pueblo people.

5. On this day in 2018, Colorado became the first state in the country to allow school nurses to administer medical marijuana to students with valid medical conditions, paving the way for access to alternative treatments for chronic illnesses.