Alagnak River

Wild & Scenic🏞 National Park
Lake and Peninsula Borough · 67 mi · Class II–III
Optimal: 800–4000 CFS · USGS #15300500
49°F — Cold water immersion risk — review cold water safety before launching
2,200 avg
18,000CFS
12.91 ft gauge height
Flood
Falling (-200 cfs/hr)(-200 in 3h)
Flow data is live from USGS·Rapid classifications and CFS ranges need community verification·Know this river?
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Avg flow: 2,200 cfsHist. median: 1,980 cfsUSGS #15300500
National Wild & Scenic River (1980) · Katmai National Park and Preserve · Bristol Bay Watershed

About

Alagnak Wild River — Bristol Bay Salmon Refuge. The river answers to no fixed line. Alagnak is a Yup'ik name that may translate to "making mistakes," and it suits a channel that wanders and rebraids across the southwestern Alaska landscape rather than holding a single course. In English it is sometimes called the Branch River, from the Yup'ik word for "branch." The USGS gauge 15300500 records a mean flow of roughly 2,200 cubic feet per second, with the optimal paddling window falling between 800 and 4,000 CFS across a river rated Class II–III.

Long before any gauge measured its water, the Alagnak was salmon country for the Yup'ik people of the Bristol Bay region. Salmon dried along the river fed Yup'ik communities through the long Bristol Bay winter, and the banks still carry the marks of that habitation — prehistoric settlements and the remains of fish camps weathered by generations. The river carried people for thousands of years, and its name is a quiet acknowledgment that it never settled into one path.

The watershed also passed through an industrial century. From the 1830s through the 1920s the Alagnak River watershed was logged to support the regional timber industry of the 1850–1910s and the railroad expansion of the 1860–1910s, with local sawmills, logging drives, and downstream lumber operations as the major operators. The exhaustion of old-growth stands around 1910, the start of state forestry conservation in 1915, and the establishment of state forests in the 1930s ended large-scale logging. The first comprehensive hydrological studies came earlier still, with USGS survey work in the 1870s–1890s and gauging-station establishment across the 1880s–1910s.

Protection came on December 2, 1980, when Congress designated 67 miles of the Alagnak as a National Wild & Scenic River as part of ANILCA, ensuring the river remains free-flowing through Katmai National Park and Preserve. The designation protects one of the finest multi-species sportfishing rivers in Alaska. The river is administered jointly by Katmai National Park and the Alaska Department of Fish and Game, and a 2009 NPS General Management Plan guides its stewardship.

Today the Alagnak endures as a working wilderness. All five species of Pacific salmon — king, sockeye, coho, pink, and chum — return here to spawn, threading the gravel alongside resident rainbow trout, Arctic grayling, and northern pike. Paddlers commonly break the river into three sections: the Upper Alagnak below Kukaklek Lake, a Class II reach known for trophy rainbow trout; the Middle Alagnak around Big Falls, the marquee Class II–III section; and the Lower Alagnak toward the Kvichak confluence, Class I–II king salmon water. The same waters that sustained generations of fish camps now draw anglers and float-trippers into one of Bristol Bay's last undimmed corners.

Solunar Fishing Activity
🌒
Waxing Crescent
26% illumination
Poor
Moon overhead
3:02 PM
Moonrise
9:39 PM
Moonset
8:26 AM
Moon underfoot
3:02 AM
Next full moon: Jul 2910 days
Outfitters
Alagnak Lodge
Multi-day float trips and fly-out fishing
10-Year Flow Patterns
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Data Quality

River conditions are community-verified. CFS ranges, difficulty ratings, and access points may not reflect every flow level or seasonal change. Always check current conditions, scout unfamiliar rapids, and paddle within your skill level.

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