Lassen County is in the Shasta Cascades region of California. This rural county sits at the confluence of the majestic Sierra Nevada mountains, the volcanic Cascade Range, and the high elevation Great Basin desert. Fishing, biking, hiking, and other outdoor activities attract most visitors to the area.
The 26 mi (42 km) Bizz Johnson trail is the county's most popular hiking and biking route. "The Bizz" follows the old Fernley and Lassen Branch Line of the Southern Pacific railroad along the Susan river canyon, traversing abandoned railroad bridges, trestles and tunnels and rewarding visitors with mountain views, beautiful fall foliage, and colorful spring wildflowers.
- 2 Modoc County - Lassen County's northern neighbor is in California's northeast corner and is home to only about 10,000 people, or slightly more than two people per square mile. Modoc County's northern and western portions have been shaped by volcanism, as evidenced by the many lava flows, cinder cones, hot springs, and volcanic mountains that visitors will encounter, while the Warner Mountain range and its many alpine lakes are found in the county's eastern side. The county is home to several wildlife refuges where bald eagles, peregrine falcons, goshawks, golden eagles, mule deer, elk, wild horses, wild burros and pronghorn antelope can be seen.
- Western Nevada
- 3 Sierra County - Located in the mountains and forests adjacent to the Nevada border, Lassen County's southern neighbor was a booming mining area during the Gold Rush, but today is home to only about 3,000 people. Historically the county was the site of several massive gold discoveries, including the 106 pound Monumental Nugget in 1869; a replica of the huge nugget can be seen in the Kentucky Mine Museum in Sierra City.
- 4 Plumas County - Located southwest of Lassen County, the forests, rivers and mountains of Plumas County were originally inhabited by Native Americans before miners arrived during the Gold Rush, followed soon after by loggers, and today tourists visit the county for its camping, fishing, whitewater, snowshoeing, and other outdoor opportunities. The Feather River Scenic Byway is a popular way to see the county's beauty, with the east-west route following California's first designated wild and scenic river past nearly one hundred waterfalls, historic bridges and tunnels, spring wildflowers, vivid fall colors, and the "Stairway of Power" consisting of seven hydroelectric powerhouses installed along the river.
- 5 Shasta County - Lassen County's northwestern neighbor is a land of mountains, lakes and rivers. Massive Shasta Lake, California's largest reservoir, is the "houseboat capital of the world", with rentals available for those who want to vacation on the water. Several spectacular waterfalls can be found in the county, including the 129 ft (39 m) Burney Falls, which Theodore Roosevelt described as "the Eighth Wonder of the World", and McCloud River Falls, which is actually three scenic waterfalls. In the county's southeastern corner, Lassen Volcanic National Park is home to a geologic hotspot highlighted by 10,457 ft (3,187 m) Lassen Volcano. The mountain can be summitted via a steep trail, but plan to do so in the summer - the park's 600–700 inches (1,500–1,800 cm) of annual snowfall make it the snowiest place in California.