Lavas

The Lavas Inventoried Roadless Area encompasses 25,864 acres within the Modoc National Forest, occupying a section of the volcanic Modoc Plateau in Modoc County, California. The terrain is defined by volcanic landforms—East Sand Butte, Little Sand Butte, Big Sand Butte, and Twin Sister—rising above the lava-flow terrain that names the area. Hydrology is minimal, centered on The Panhandle headwaters, reflecting the porous volcanic substrate that allows precipitation to percolate rapidly into the subsurface rather than forming persistent surface drainages.

Ecological communities reflect the area's position at the intersection of the Great Basin, Columbia Plateau, and Sierra Nevada bioregions. Great Basin Big Sagebrush Shrubland and Great Basin Big Sagebrush Steppe dominate the level terrain, with big sagebrush (Artemisia tridentata), antelope bitterbrush (Purshia tridentata), and rubber rabbitbrush (Ericameria nauseosa) forming the shrub matrix over bluebunch wheatgrass (Pseudoroegneria spicata) and bottlebrush squirrel-tail (Elymus elymoides). Columbia Plateau Western Juniper Woodland rises above the sagebrush on the butte slopes, with western juniper (Juniperus occidentalis) and curl-leaf mountain-mahogany (Cercocarpus ledifolius) on rocky outcrops. Pacific Northwest Wooded Lava Flow is the area's most distinctive community—a regionally rare type in which ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta) colonize the interstices of fractured basalt flows, with desert-sweet (Chamaebatiaria millefolium) and mountain wildmint (Monardella odoratissima) in the open understory. The volcanic daisy (Erigeron elegantulus), a species characteristic of the Modoc Plateau's open lava terrain, is recorded in the area.

Two federally listed plant species occur in the area: Green's awnless Orcutt grass (Tuctoria greenei), federally Endangered, and slender Orcutt grass (Orcuttia tenuis), federally Threatened—both native to the seasonal wetland habitats of northern California. Pinyon jay (Gymnorhinus cyanocephalus), IUCN-vulnerable, ranges through the juniper woodland, exploiting western juniper cone crops. Olive-sided flycatcher (Contopus cooperi), IUCN near threatened, uses the open snag-rich edges of the ponderosa pine lava-flow forest. Townsend's big-eared bat (Corynorhinus townsendii), IUCN-vulnerable, uses the crevice habitat of the lava flow terrain for roosting. Northern spotted owl (Strix occidentalis caurina), federally Threatened, is recorded in the forest zones of this area. Portions of this area fall within the potential range of several federally listed species; see the Conservation section for details.

Moving through the Lavas area is unlike traversing conventional mountain terrain. The Pacific Northwest Wooded Lava Flow presents open ponderosa and lodgepole pine forest above fractured basalt and cinder—a landscape of rough volcanic rock with a thin mat of sagebrush and forb understory. The buttes—East Sand Butte, Big Sand Butte—rise as prominent landmarks above the surrounding plateau, providing elevated viewpoints across the Modoc Plateau toward the Medicine Lake Highlands and, on clear days, the distant peaks of the southern Cascades and northern Sierra Nevada.

The volcanic plateau terrain of the Lavas Inventoried Roadless Area lies within one of the most densely inhabited Indigenous landscapes in northeastern California. Federal surveys and the accounts of early Euro-American explorers documented evidence of Indian use and occupancy across virtually every township of land within or adjacent to what would become the Modoc National Forest—"there is hardly a township of land anywhere within or adjacent to the Modoc Forest which has not given evidence of Indian use and occupancy." [2]

Three principal peoples shared and contested the region before Euro-American settlement. The Modoc people occupied the area around Clear Lake and Tule Lake in northwestern Modoc County, extending along the Lost River and south into the lava bed country. [2] Originally an offshoot of the Klamath tribe to the north, the Modoc had developed a distinct cultural identity and fiercely defended their territorial boundaries against neighboring peoples. [2] The Pit River (Achumawi) people—one of the most populous tribes in California—ranged from the headwaters of the Pit River into Fall River Valley; their range encompassed the southern portion of what is now the Modoc National Forest. [2] The Northern Paiute, pushing westward from the Idaho mountain country, occupied the eastern portions of Modoc County and the Surprise Valley country. [2]

Euro-American contact brought violent disruption. The discovery of gold in California brought settlers who encroached on Modoc and Pit River territories through the 1850s. Cattle drovers reached Surprise Valley as early as 1853, and the biggest single year of settlement came in 1864, when cattle ranchers established themselves throughout the region. [3] The Modoc War of 1872–1873—in which Modoc leader Captain Jack (Kintpuash) and a band of followers held U.S. Army forces at bay for months in the nearby lava beds of Tule Lake—ended with the execution of Captain Jack and the forced removal of most surviving Modoc to Indian Territory in Oklahoma.

Ranching and homesteading defined land use in the region through the late nineteenth and early twentieth centuries. The Forest Homestead Law of June 11, 1906 brought settlers to the Modoc country, primarily between 1910 and 1916, though most homesteads failed in the harsh climate and were eventually abandoned. [2] When the Doublehead District—within which the Lavas area lies—was added to the Modoc National Forest in 1920, the Forest Service inherited 34 homestead claims in the Clear Lake hills; nearly all were eventually abandoned and reverted to sagebrush. [2]

Federal protection arrived through the forest reserve system. The Modoc National Forest's predecessor reserves were created by Presidential Proclamation in 1904; four years later, President Theodore Roosevelt consolidated them into the Modoc National Forest. [1] The 25,864-acre Lavas Inventoried Roadless Area, within the Doublehead Ranger District of Modoc County, California, is protected under the 2001 Roadless Area Conservation Rule.

Vital Resources Protected

• Lava Flow Habitat and Roosting Sites for Sensitive Bats: The Pacific Northwest Wooded Lava Flow community—the Lavas area's most ecologically distinctive community type—preserves a rare combination of fractured basalt crevice terrain and open ponderosa pine and lodgepole pine forest that provides critical roosting habitat for Townsend's big-eared bat (Corynorhinus townsendii), IUCN-vulnerable. This bat species requires undisturbed rock crevices and cave-like spaces for maternity roosting and hibernation; lava flow terrain provides these features at a scale difficult to find elsewhere in the Modoc Plateau landscape. The roadless condition prevents road construction that would fragment the contiguous lava flow habitat and introduce noise, light, and vehicle traffic that disturb bat colonies during sensitive reproductive and hibernation periods.

• Sagebrush Steppe Habitat for Grassland-Dependent Species: Great Basin Big Sagebrush Shrubland and Columbia Plateau Steppe and Grassland—the dominant communities across the lower terrain of the Lavas area—provide nesting and foraging habitat for pinyon jay (Gymnorhinus cyanocephalus), IUCN-vulnerable, and olive-sided flycatcher (Contopus cooperi), IUCN near threatened. These communities are among the most threatened habitats in the western United States, declining from conversion, invasive annual grasses, and altered fire regimes. The area's roadless condition preserves intact sagebrush and native bunchgrass cover that sustains these communities' ecological function without the disturbance corridors that accelerate non-native grass invasion.

• Interior Forest Habitat for Northern Spotted Owl: The conifer forest zones of the Lavas area support northern spotted owl (Strix occidentalis caurina), federally Threatened, in one of the more arid and eastern portions of this species' range on the Modoc Plateau. This population occupies the transition between the Pacific Northwest forest zone and the Great Basin, representing an ecologically distinct range segment. The roadless condition preserves the interior forest conditions—minimal edge disturbance, structural complexity, and low human access—that northern spotted owl requires for successful nesting.

Potential Effects of Road Construction

• Lava Flow Habitat Fragmentation and Bat Disturbance: Road construction through the basalt lava flow terrain would require blasting and grading of fractured rock—activity that destroys the crevice systems used by Townsend's big-eared bat for roosting and hibernation. Vehicle traffic along roads through lava flow terrain introduces light pollution, noise, and human disturbance at levels that cause abandonment of maternity colonies during the critical spring-summer period. Lava flow crevice systems, once disturbed by blasting or grading, cannot be restored, making any loss of bat roosting habitat irreversible.

• Invasive Grass Establishment in Sagebrush Communities: Road construction and associated vehicle traffic are the primary vectors for cheatgrass (Bromus tectorum) invasion in Great Basin sagebrush communities. On the Modoc Plateau, where native bunchgrass communities still retain significant integrity in undisturbed areas, road construction would create dispersal corridors for cheatgrass into currently intact sagebrush. Once established, cheatgrass increases fire frequency—converting sagebrush shrubland to annual grassland—and eliminating the shrub structure on which pinyon jay and other sagebrush-dependent species depend for nesting and food resources.

• Sedimentation in the Panhandle Headwater System: Although surface hydrology is limited in the lava flow terrain, The Panhandle headwaters represent the primary surface water system in the Lavas area. Road construction on slopes above this system would generate fine sediment from exposed mineral soil on road cuts and fills—sediment that would accumulate in the headwater channels and reduce the habitat quality of the aquatic habitats that support northwestern pond turtle (Actinemys marmorata), Proposed Threatened, and contribute to the hydrological function of this arid-plateau watershed.

The Lavas Inventoried Roadless Area provides 25,864 acres of dispersed backcountry terrain on the volcanic Modoc Plateau in Modoc County, California. No maintained trails, designated trailheads, or developed campgrounds are located within the roadless area boundary. Recreation here is primarily dispersed—cross-country travel through the sagebrush steppe and the Pacific Northwest Wooded Lava Flow, with access from adjacent Modoc National Forest roads.

Dispersed Recreation and Cross-Country Travel

The area's defining terrain feature is the Pacific Northwest Wooded Lava Flow community, where ponderosa pine and lodgepole pine grow from fractured basalt flows above the sagebrush plateau. Travel through this terrain requires care on the irregular, creviced basalt surface. The buttes—East Sand Butte, Big Sand Butte, Little Sand Butte, and Twin Sister—rise as navigable high points with elevated views across the Modoc Plateau toward the Medicine Lake Highlands and, on clear days, the southern Cascades and northern Sierra Nevada. The surrounding sagebrush and bunchgrass steppe of the Columbia Plateau and Great Basin communities provides open walking terrain accessible from the perimeter roads.

Dispersed camping is available throughout the area under standard Modoc National Forest regulations. The limited surface hydrology of the lava plateau—with water available primarily at The Panhandle headwaters—makes water sourcing a planning consideration for extended backcountry trips.

Birding

The Lavas area is surrounded by one of the most productive birding landscapes in California. Sixteen eBird hotspots within 24 kilometers record up to 212 species. Tule Lake National Wildlife Refuge leads the region with 212 species recorded at the Auto Tour (630 checklists), 202 species at Sump 1B, and multiple additional monitoring points exceeding 100 species. Lava Beds National Monument logs 202 species across 410 checklists at the main monument hotspot, and its Captain Jack's Stronghold records 127 species in 157 checklists—a historically significant site within the lava bed landscape directly adjacent to the Lavas roadless area. Medicine Lake, 14 miles from the area's edge, records 113 species in 104 checklists. Within the Lavas roadless area itself, the sagebrush and lava flow terrain attracts species characteristic of the Great Basin-Modoc Plateau interface. Pinyon jay (Gymnorhinus cyanocephalus), IUCN-vulnerable, is recorded in the juniper woodland zones. Sage thrasher (Oreoscoptes montanus), Brewer's sparrow (Spizella breweri), and other sagebrush specialists use the shrubland terrain.

Hunting

The sagebrush and forested lava terrain of the Lavas area supports mule deer and other game species. Hunting is a traditional use of the Modoc National Forest lands in this portion of Modoc County and is subject to California Department of Fish and Wildlife regulations.

The dispersed, non-motorized character of recreation in the Lavas area—cross-country travel through volcanic terrain that cannot support conventional trail construction, birding in lava-flow forest adjacent to one of California's premier raptor and waterfowl viewing corridors—depends entirely on the area's roadless condition. Road construction would fragment the contiguous lava flow habitat, introduce motorized traffic into currently quiet terrain, and eliminate the undisturbed sagebrush connectivity that extends from the Lavas roadless interior to the Tule Lake and Lava Beds National Monument birding complex.