1. Wyoming became a state: On June 30, 1890, Wyoming officially became the 44th state in the United States. This was a significant moment in Wyoming's history as it marked the end of a long struggle for statehood and the beginning of a new era for the Cowboy State.

2. Construction of Yellowstone National Park: In 1908, on June 30th, the construction of Old Faithful Inn began in Yellowstone National Park. The inn is now a National Historic Landmark and is a popular tourist destination in the park.

3. The discovery of oil in Wyoming: On June 30, 1910, oil was discovered in Wyoming's Salt Creek Oil Field, which is one of the largest oil reserves in the United States. This discovery had a significant impact on the state's economy and helped establish Wyoming as a major player in the oil industry.

4. Fossil discovery: On June 30, 1961, a dinosaur fossil was discovered near Medicine Bow, Wyoming. The fossil collection is now housed in the University of Wyoming's Geological Museum and is considered one of the most extensive collections of dinosaur fossils in the world.

5. Women's suffrage victory: Wyoming was the first state in the United States to grant women the right to vote. On June 30, 1869, the Wyoming Territory passed the Suffrage Act, which allowed women to vote and run for office. This was a significant achievement in the fight for women's rights and helped pave the way for suffrage movements across the country.