1. On July 18, 1806, the famous Lewis and Clark Expedition reached the Three Forks of the Missouri River, where they decided to split up in order to explore more territory. Captain Meriwether Lewis went north to explore the Marias River, while Captain William Clark went south to explore the Yellowstone River.

2. July 18, 1969, marks the day when the infamous "Manson Family" arrived at the Barker Ranch in Death Valley, California, shortly before they were arrested for the gruesome murders they had committed.

3. In 1954, the Montana Women's Prison opened in Billings on July 18, becoming the first women's prison in Montana. Prior to its opening, women were housed in the same prison as men.

4. On July 18, 1988, a massive fire swept through Yellowstone National Park, burning over 1.2 million acres of land and destroying hundreds of buildings. The fire was caused by a combination of hot and dry weather, along with centuries of fire suppression policies that had led to a buildup of fuel that was just waiting for a spark.

5. In 1862, during the Civil War, the Battle of Fort Wagner took place on July 18, which was famously depicted in the film "Glory." The battle was fought off the coast of South Carolina, and the Union forces, which included the all-black 54th Massachusetts Infantry Regiment, were ultimately defeated by the Confederates.