1. On May 18, 1934, the infamous Dust Bowl reached its peak in Oklahoma when a massive dust storm covered the state and surrounding areas, leading to tremendous damage to crops, livestock, and homes. This event contributed to the Great Depression and resulted in significant migration from the area.

2. May 18, 2002, was a significant day for tornadoes in Oklahoma as multiple twisters touched down in different parts of the state, causing damage and loss of life. One of the most devastating was an F4 tornado that hit near the town of Apache, leaving a trail of destruction and killing 11 people.

3. In one of the most significant developments in Oklahoma energy history, on May 18, 1901, the first commercial oil well was drilled in the state, ushering in a new era of industry and growth. The site of the well, known as the Nellie Johnstone No. 1, is now marked by a commemorative monument.

4. On May 18, 1980, a landmark event in science and space exploration took place when Oklahoma astronaut Tom Stafford launched on his fourth mission in space, serving as commander of the Apollo-Soyuz Test Project, which was the first joint American-Soviet manned mission.

5. May 18, 1907, was a major milestone in Oklahoma's early history, as it marked the day the state was officially admitted to the Union as the 46th state. The occasion was celebrated with great pomp and ceremony, and Oklahoma's place as a vital part of the United States was cemented for generations to come.