Tasnuna River

The Tasnuna River roadless area encompasses 348,866 acres of the Chugach Mountains in southeastern Alaska, rising from sea-level valleys to alpine summits including Mount Chosin Few at 8,084 feet and Cordova Peak at 7,730 feet. Water is the organizing force of this landscape. Outlet Schwan Glacier feeds the Tasnuna River, which flows through the area's core drainage alongside tributary systems including the Allen River, Cleave Creek, Ginny Creek, and Jackson Creek. These waterways originate in alpine snowfields and glacial melt, carving through steep terrain and creating the hydrological backbone that sustains all life here—from the smallest aquatic invertebrates in cold headwater streams to the salmon that return annually to spawn.

Forest composition shifts dramatically with elevation and moisture. In lower valleys, Sitka Spruce - Black Cottonwood Forest dominates, with Sitka spruce (Picea sitchensis) and balsam poplar (Populus balsamifera) forming a dense canopy that filters light to a shadowed understory. As elevation increases and moisture becomes more abundant, this forest transitions to the Alaskan Pacific Maritime Subalpine Alder-Salmonberry Shrubland, where Sitka alder (Alnus viridis subsp. sinuata) and salmonberry (Rubus spectabilis) create an impenetrable thicket interspersed with Devil's Club (Oplopanax horridus). Above the shrubline, the Alaskan Pacific Maritime Alpine Floodplain and Mesic Herbaceous Meadow communities take hold, where low-growing plants including Sitka willow (Salix sitchensis), dwarf fireweed (Chamaenerion latifolium), purple saxifrage (Saxifraga oppositifolia), and unalaska paintbrush (Castilleja unalaschcensis) carpet the ground. Bogbean (Menyanthes trifoliata) and western bunchberry (Cornus unalaschkensis) occupy wetter microsites throughout these upper elevations.

The animal communities reflect this vertical zonation. Coho salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) move through the river system, their seasonal migrations triggering a cascade of predation and nutrient cycling that reaches far inland—brown bears (Ursus arctos) and bald eagles (Haliaeetus leucocephalus) intercept spawning runs, redistributing marine nutrients across the watershed. In alpine meadows and rocky slopes, mountain goats (Oreamnos americanus) navigate vertical terrain, while moose (Alces alces) browse the shrublands and forest edges. Wood frogs (Lithobates sylvaticus) and western toads (Anaxyrus boreas) occupy wetland and riparian habitats. In nearshore waters, the endangered sea otter (Enhydra lutris) (IUCN) and harbor seals (Phoca vitulina) hunt in the cold currents where freshwater from the Tasnuna system meets the ocean.

A person traveling through this landscape experiences rapid ecological transitions. Following the Tasnuna River upstream from tidewater, the traveler passes through dense Sitka spruce forest where light barely penetrates the canopy and the air holds the smell of wet soil and decomposing wood. As elevation increases, the forest opens into alder and salmonberry thickets—the understory becomes a physical barrier, and the soundscape shifts from the muted drip of water in the forest to the rush of faster-moving creeks. Breaking through the shrubline onto alpine meadows brings sudden exposure: the view expands across the Chugach peaks, wind replaces the enclosed quiet of the forest, and the ground underfoot transitions from soft duff to low herbaceous plants and exposed rock. The streams here run clear and cold, originating from snowfields visible on the higher ridges. This vertical compression—from sea-level temperate forest to alpine tundra within a few miles of travel—defines the Tasnuna River experience.

Indigenous peoples inhabited this landscape for over 10,000 years. The Eyak, known as the "Wild Copper River Salmon People," were the primary inhabitants of the Copper River Delta and lower Copper River, including the Tasnuna River area. While major Eyak villages such as Alaganik and Eyak were located closer to the coast near present-day Cordova, the inland river valleys like the Tasnuna were used for seasonal camps and transit. The Ahtna people historically inhabited the Copper River Basin to the north, and the Copper River served as one of the few navigable corridors through the Chugach Mountains, connecting the Gulf of Alaska to the interior and enabling trade and resource gathering among Indigenous groups in the region.

During the early twentieth century, the Tasnuna River area became part of a major transportation and industrial corridor. The Copper River and Northwestern Railway, built between 1908 and 1911, ran from Cordova to the Kennecott copper mines and passed along the western bank of the Copper River, with a segment extending to the Tasnuna River. The railway included 129 bridges between Cordova and Chitina and served as the primary means of transporting high-grade copper ore from the interior to the deep-water port at Cordova for shipment to smelters in Washington state. The industrial era of the region effectively ended in 1938 when the Kennecott mines closed and the Copper River and Northwestern Railroad was abandoned. The final train ran in November 1938, and the line was permanently severed by ice breakup at the Chitina crossing in 1939.

The area was first mapped by Lieutenant Henry Tureman Allen of the U.S. Army, who led the first recorded exploration of the Copper and Tasnuna River regions in 1885. Subsistence use of timber resources has been permitted historically, with local residents, miners, and settlers allowed to take green or dry timber from the forest for personal use such as fuelwood, cabin logs, and fencing without a permit, except for green saw timber. Commercial logging has been minimal; less than 2 percent of the entire Chugach National Forest is considered suitable for commercial timber operations.

Federal protection of the area began when President Theodore Roosevelt established the Chugach National Forest on July 23, 1907, by Presidential Proclamation under the authority of the Forest Reserve Act of 1891 and the Organic Administration Act of 1897. The forest was created from portions of the Afognak Forest and Fish Culture Reserve, which had been designated in 1892. On July 2, 1908, an Executive Order consolidated the Chugach National Forest and the Afognak Forest and Fish Culture Reserve under the single name of the Chugach National Forest. On February 23, 1909, President Roosevelt issued another proclamation significantly enlarging the forest boundaries to include additional lands in the Prince William Sound and Copper River regions. Between 1910 and 1915, several proclamations and executive orders excluded specific tracts of land for settlement, mining, or townsite development. In 1971, the Tasnuna River region was part of the lands involved in the settlement of aboriginal claims under the Alaska Native Claims Settlement Act.

The Tasnuna River is a 348,866-acre Inventoried Roadless Area protected under the 2001 Roadless Area Conservation Rule within the Chugach National Forest, managed by the Cordova Ranger District.

Vital Resources Protected

Glacial Headwater System Supporting Anadromous Fish Populations

The Tasnuna River drainage originates in the Schwan Glacier outlet and flows through intact alpine and subalpine ecosystems that regulate water temperature, timing, and sediment load—conditions essential for salmon spawning and rearing. The roadless condition preserves the unbroken riparian corridor from high-elevation snowmelt sources through Sitka Spruce–Black Cottonwood forests to tidewater, maintaining the cold, clear water conditions that anadromous fish species require for successful reproduction and juvenile development. Road construction would fragment this gradient and degrade the water quality that sustains the commercial and subsistence fisheries dependent on these populations.

Alpine and Subalpine Climate Refugia Connectivity

The area's steep elevation gradient—from tidewater to over 8,000 feet at Mount Chosin Few—creates a mosaic of distinct climate zones across the Alaskan Pacific Maritime Subalpine Alder-Salmonberry Shrubland and Alpine Floodplain ecosystems. This elevational connectivity allows plant and animal populations to shift upslope or downslope in response to changing temperature and precipitation patterns, a critical adaptation mechanism as regional climate changes. Roads would sever these elevational corridors by creating barriers and introducing edge effects that fragment habitat patches and prevent species movement between refugia.

Nearshore Marine Ecosystem Support Through Freshwater Discharge

The Tasnuna River system delivers nutrient-rich freshwater and sediment to coastal waters, supporting the marine food web upon which sea otters (Enhydra lutris, endangered, IUCN) and other marine mammals depend. The roadless condition preserves the hydrological integrity of the entire drainage—from glacial headwaters through floodplain wetlands to estuary—ensuring that freshwater discharge patterns, sediment transport, and nutrient cycling remain unaltered. Road construction and associated hydrological disruption would reduce freshwater input to nearshore habitats, degrading the productivity of the marine ecosystem that sea otters rely on for foraging.

Intact Floodplain and Wetland Function

The Alaskan Pacific Maritime Alpine Floodplain and associated Mesic Herbaceous Meadows form a hydrologically connected network that stores water during snowmelt, moderates streamflow, and filters sediment before it reaches downstream channels. These wetland-upland transition zones are particularly vulnerable to disruption in high-precipitation maritime environments where water moves rapidly through the landscape; their roadless condition allows natural flood dynamics and sediment deposition to continue unimpeded. Road fill, culverts, and drainage would fragment this system, altering water storage capacity and increasing downstream erosion and sedimentation.

Threats from Road Construction

Sedimentation and Temperature Increase in Spawning Habitat

Road construction on steep alpine and subalpine terrain requires extensive cut slopes and fill placement, exposing bare soil and rock to the high precipitation typical of the Chugach Mountains' maritime climate. Erosion from these disturbed slopes would deliver fine sediment into the Tasnuna River and its tributaries, smothering spawning gravel and reducing water clarity—conditions that directly impair salmon egg incubation and juvenile visibility for feeding. Additionally, removal of riparian forest canopy along road corridors would increase solar radiation reaching the water surface, raising stream temperatures in a system where cold water is already a limiting factor for cold-water fish species.

Fragmentation of Elevational Connectivity and Loss of Refugia Function

Road construction through the elevation gradient would create a linear barrier and associated edge habitat that disrupts the movement of alpine and subalpine species between climate zones. The disturbed corridor would favor invasive plant species adapted to road edges and compacted soil, outcompeting native alpine vegetation and reducing the quality of refugia habitat at higher elevations. Species dependent on shifting their range upslope as temperatures warm—including plants and animals adapted to the Subalpine Alder-Salmonberry Shrubland and Alpine Floodplain—would face fragmented habitat patches separated by unsuitable road-edge conditions, reducing their capacity to track suitable climate conditions.

Hydrological Disruption of Floodplain and Estuary Function

Road fill and culvert placement in the floodplain would alter natural water storage and flow patterns, reducing the area's capacity to absorb and slowly release snowmelt and rainfall. This disruption would increase peak streamflow during high-water events, accelerating erosion and sediment transport downstream, while reducing baseflow during dry periods—changes that degrade both freshwater habitat and the estuarine conditions that support the nearshore marine ecosystem. The loss of floodplain water storage would particularly affect sea otter (Enhydra lutris) populations by reducing the productivity of nearshore foraging habitat through altered freshwater discharge and nutrient cycling.

Chronic Erosion and Sediment Loading from Road Maintenance

Roads in high-precipitation maritime mountains require ongoing maintenance, including drainage work, surface grading, and slope stabilization—activities that generate continuous sediment input to streams over decades. This chronic erosion, distinct from initial construction impacts, would persistently degrade water clarity and alter substrate composition in the Tasnuna River drainage, preventing recovery of spawning habitat and maintaining elevated turbidity that reduces fish feeding efficiency and growth rates. The roadless condition eliminates this long-term sediment source and allows the system's natural sediment transport processes to function without anthropogenic disruption.

The Tasnuna River Roadless Area spans 348,866 acres of the Chugach Mountains in southeastern Alaska, encompassing alpine terrain, subalpine shrubland, and Sitka spruce–black cottonwood forest. Four maintained trails provide foot access into the area: Heney Glacier Trail, Shiels Glacier Trail, Jackson Creek Trail, and Cleave Creek Trail. All recreation here depends on the roadless condition—access is by foot, floatplane, or watercraft, and the absence of roads preserves the intact watersheds and unfragmented habitat that support the area's hunting, fishing, and paddling opportunities.

Hunting

The Tasnuna River area lies within Alaska Game Management Unit 6B and supports hunting for brown bear, black bear, moose, mountain goat, Dall sheep, ptarmigan, grouse, wolf, wolverine, and waterfowl including ducks and geese. Brown bear seasons run September 15–December 31 and March 15–May 31, with a harvest limit of one bear every four regulatory years. Mountain goat season runs September 1–April 30; nonresident hunters must complete a Mountain Goat Identification quiz and be guided. Moose hunting in the Unit 6B Controlled Use Area (August 25–September 4) prohibits motorized vehicle use except on the Copper River Highway and at designated boat launches. Ptarmigan inhabit upper slopes; grouse are found in spruce thickets. Wolf and wolverine hides must be sealed within 30 days of harvest. Nonresident moose hunters must complete a Nonresident Moose Hunter Orientation course. Access is via floatplane or boat through the Copper River drainage or from the Clear Creek Boat Launch; the roadless condition preserves the remote character essential to this hunting experience.

Fishing

The Tasnuna River and its tributaries support wild populations of Chinook salmon, sockeye salmon, coho salmon, Dolly Varden, Arctic grayling, and rainbow trout. No hatchery stocking occurs in the roadless area; wild fish populations are sustained by intact spawning and rearing habitat. Fishing is regulated by Alaska Department of Fish and Game and Federal Subsistence Management. Nonresident anglers must immediately record harvested king salmon on their license. Daily limits include 10 Dolly Varden or Arctic char, 10 Arctic grayling, and steelhead trout of 36 inches or longer (1 per day, 2 in possession, 2-fish annual limit). In freshwater, only single-point hooks are allowed for salmon. Access is by floatplane to gravel bars, jet boat or raft via the Copper River confluence, or on foot via the maintained trails. The roadless designation preserves the cold, undisturbed headwater streams and floodplain ecosystems that are critical to salmon spawning and rearing.

Paddling

The Tasnuna River is a Class II+ to Class III whitewater destination for kayaking, rafting, and packrafting. The main run extends approximately 23 miles from upper gravel bars to the Copper River confluence. Put-in access is via bush plane to upper gravel bars or to glacial tributaries at approximately 900-foot elevation on the south side of the valley. Take-out is at the Tasnuna–Copper River confluence; paddlers may continue downstream to take-outs near Cordova. The river is glacial-fed, fast and cold, with large waves and braided channels in the lower section. Afternoon headwinds from the Copper River are a documented hazard on the lower 20 miles. Seasonal flow peaks in July; the river is runnable in summer months when temperatures range from the 40s to 60s Fahrenheit. The Tasnuna has been used as a segment of the Alaska Mountain Wilderness Classic. Access depends entirely on air charter or wilderness traverse; the roadless condition ensures that paddlers experience the river in its natural state, with cold, intact watersheds and undisturbed riparian habitat.