September 4 is an important day in Wyoming history, marked by significant events that have shaped the state's past and present. Here are five interesting facts about this day in Wyoming history:

1. The first railroad train arrived in Laramie. On September 4, 1868, the Union Pacific railroad brought its first train to Laramie, Wyoming. The town was an important stop on the transcontinental railroad, and the arrival of the train marked the beginning of a new era of growth and prosperity for Laramie.

2. Wyoming's first air show was held in Casper. On September 4, 1920, Casper hosted its first air show, featuring a number of daring pilots performing stunts and aerial acrobatics. The show was a great success and helped to make aviation a popular pastime in Wyoming.

3. Wyoming became the first state to allow women to vote. On September 4, 1869, the Wyoming Territorial Legislature passed a bill allowing women the right to vote, making Wyoming the first state to grant women suffrage. This marked an important step forward in the struggle for women's rights.

4. The world's first national park was established in Wyoming. On September 4, 1872, President Ulysses S. Grant signed a bill creating Yellowstone National Park, the first national park in the world. The park is home to some of the most geologically active and diverse landscapes in the world, and has become one of the most popular tourist destinations in Wyoming.

5. The deadliest train wreck in Wyoming history occurred near Rock Springs. On September 4, 1911, two freight trains collided near Rock Springs, Wyoming, killing eleven people and injuring dozens more. The tragedy was a stark reminder of the dangers of the railroad industry, and led to improvements in safety regulations and equipment.