Chichagof Island sustains the highest brown bear density on Earth—roughly one grizzly per two square miles across 2,060 square miles of temperate rainforest, tidal flats, and salmon-rich watersheds within Tongass National Forest. The island's Tlingit name, Kootznoowoo, translates to "fortress of the bears," a designation validated by biologists who estimate the resident population at 1,100 to 1,500 individuals. Unlike interior Alaska grizzlies, Chichagof's coastal bears access spawning pink, chum, coho, and sockeye salmon from July through October, a protein abundance that produces larger body mass and concentrated aggregations along stream corridors. The U.S. Forest Service requires permitted operators and a seven-dollar-per-person conservation fee for access to designated viewing corridors, a framework established in 1992 to balance wildlife observation with habitat integrity. Chichagof Island tour brown bear search expeditions depart from Hoonah on Icy Strait, the only year-round settlement on the island's northeast shore. Floatplane sorties cover the western coastline and interior lake systems, targeting stream mouths where bears fish during peak salmon runs. Ground-based excursions follow salmon-bearing creeks within walking distance of Icy Strait Point, the restored cannery complex that now serves as Alaska's largest privately owned cruise destination. Both modalities operate under USFS wildlife observation protocols: 50-yard minimum distance, no food storage within viewing zones, and immediate withdrawal if a bear exhibits stress behaviors. These regulations emerged from decades of research at Pack Creek on Admiralty Island, a parallel brown bear sanctuary 30 miles southeast, where habituated viewing patterns informed best practices across Southeast Alaska. The island's ecological productivity stems from maritime climate and glacial geography. Annual precipitation exceeds 100 inches, sustaining old-growth Sitka spruce and western hemlock that stabilize stream banks and provide thermal cover. Glacial retreat over the past 10,000 years carved a dendritic network of fjords, bays, and estuaries that funnel anadromous fish into concentrated corridors—ecological bottlenecks that grizzlies exploit with surgical timing. Sow bears with cubs occupy lower-gradient streams where escape terrain is accessible; mature boars dominate prime fishing sites at waterfall plunge pools and tidal confluences. This spatial hierarchy, visible during peak salmon runs, offers a real-time illustration of ursine social structure unmatched in accessibility anywhere in North America.