Modoc County is in the Shasta Cascades region of California in the extreme northeastern corner of the state. It is home to only about 10,000 people, or slightly more than two people per square mile. The 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.
- 1 Tule Lake National Monument — one of the sites where Japanese-Americans were interned during World War II
- Southern Oregon
- Western Nevada
- 1 Lassen County - Located south of Modoc County, rural Lassen 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, with the 26 mi (42 km) Bizz Johnson trail 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 Shasta County - Modoc County's southwestern 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.
- 3 Siskiyou County - Modoc County's western neighbor is dominated by 14,179 ft (4,322 m) Mount Shasta, the west coast's second-tallest volcano, towering nearly 10,000 feet (3,000 m) above its surroundings; while a summit climb requires advanced mountaineering skills, its lower slopes are great for hiking, backpacking and cross-county skiing. The Volcanic Legacy Scenic Byway links Mount Shasta to Lava Beds National Monument in the county's northeast, home to over 800 lava tube caves, several of which are open to exploration. The county is also a premier destination for birdwatchers, with nearly two million birds passing through Lower Klamath National Wildlife Refuge and Tule Lake National Wildlife Refuge during migrations, and North America’s largest concentration of snow geese arriving in spring.