1. In 1828, Jedediah Smith, the famous explorer who blazed the trail to California, passed through the Mojave Desert with a small group of fur trappers on April 26th.

2. On April 26, 1850, the first California State Constitutional Convention was held in Monterey, California. The convention lasted 10 weeks and ended with California being admitted to the Union as the 31st state on September 9, 1850.

3. In 1913, a group of young boys discovered the La Brea Tar Pits while playing in a field in what is now Hancock Park in Los Angeles. Today, the La Brea Tar Pits are one of the most famous fossil sites in the world and contain the largest and most diverse assemblage of Ice Age plants and animals anywhere.

4. The deadliest earthquake in US history occurred in San Francisco on April 18, 1906, but it wasn't until April 26th that the city finally got some much needed assistance. The US Army arrived in San Francisco on this day to help with search and rescue efforts and to restore order to the devastated city.

5. The first-ever Earth Day was held on April 22, 1970, but in California, Earth Day events occurred all week, leading up to the official day. On April 26th, 1970, the University of California, Berkeley held a day-long teach-in, with lectures, workshops, and panel discussions about various environmental issues.