Big Nasty Trail Start, Tulelake, Ca

A loop trail, Big Nasty is 2 miles (3.2 km) long. Named after a brush-covered rough lava area just to the north— “it is big and it is nasty!” From the Mammoth Crater/Hidden Valley pullout, the trail starts along the crater rim. Turn left from the Mammoth Crater Trail. Due to the impacts of the 2021 Antelope Fire we ask that visitors stay on the marked trail. Lava Beds has twelve hiking trails. The most popular trails are short, but lead to interesting historic sites and geological features. Due to resource concerns, pets and bicycles are not permitted on any park trails, on in non-developed area or caves. All trails cross or enter the non-developed backcountry, while the long trails are primarily in designated wilderness areas. The trails in this bulletin are arranged by their distance from the visitor center. Carry plenty of water regardless of trail length—no surface water exists at Lava Beds. Watch for rattlesnakes and wear sunscreen and a hat in summer. Be prepared for sudden weather changes any time of year. Pets, bicycles, hunting, and motorized vehicles are not permitted in wilderness areas. No person may camp in a non-developed or wilderness area with a group size of more than twelve, including horses and pack animals. Due to the dry nature of Lava Beds, especially in summer, open fires are not allowed at any time in the backcountry. Gas stoves are permitted. Other restrictions may apply during extreme fire conditions—please check with a ranger. Camping in or within 50 yards (46 km) of caves or in the vicinity of chimneys is not permitted. Camping within 0.25 miles (0.4 km) of roads, trailheads, and parking areas is also prohibited. Check at the visitor center for current weather information. Carry first aid supplies and let someone know where you are going and when you plan to return. Off-trail hiking is not recommended, as lava terrain is very rough. Please remember to leave no trace. If you pack it in, pack it out. Leave what you find. All historic and prehistoric objects, plants, animals, and rocks are protected. Please store your food securely and do not share your lunch with any wild animals.