On March 10, 1957, the United States Army Corps of Engineers completed The Dalles Dam and inundated Celilo Falls, the oldest continuously inhabited site in North America and a cultural and economic hub for Indigenous people. In the negotiation of treaties between the United States, nearly one hundred years earlier, Indigenous leaders reserved access to Columbia River fishing sites as they ceded territory and retained smaller reservations. In the years before the dam's completion, leaders, many of who were the descendants of earlier treaty signatories, attempted to stop the dam and protect both fishing sites from the encroachment of state and federal regulations and archaeological sites from destruction. This study traces the work of Wilson Charley, a Native fisherman, a member of the Yakama Nation's Tribal Council, and great-grandson of one of the 1855 treaty signatories. More broadly, this study places Indigenous actors on a twentieth-century Columbia River while demonstrating that they played active roles in the protest and management of areas affected by The Dalles Dam. Using previously untapped archival sources--a substantial cache of letters--my analysis illustrates that Charley articulated multiple strategies to fight The Dalles Dam and regulations to curtail Native's treaty fishing rights. Aiming to protect the 1855 treaty and stop The Dalles Dam, Charley created Native-centered regulatory agencies. He worked directly with politicians and supported political candidates, like Richard Neuberger, that favored Native concerns. He attempted to build partnerships with archaeologists and landscape preservationists concerned about losing the area's rich cultural sites. Even after the dam's completion, he conceptualized multiple tribal economic development plans that would allow for Natives' cultural and economic survival. Given the national rise of technological optimism and the willingness for the federal government to terminate its relationship with federally recognized tribes, Charley realized that taking the 1855 treaty to court was too risky for the political climate of the 1950s. Instead, he framed his strategies in the language of twentieth-century conservation, specifically to garner support from a national audience of non-natives interested in protecting landscapes from industrial development. While many of these non-native partners ultimately failed him, his strategies are noteworthy for three reasons. First, he cast the fight to uphold Native treaty rights in terms that were relevant to non-natives, demonstrating his complex understanding of the times in which he lived. Second, his strategies continued an ongoing struggle for Natives to fish at their treaty-protected sites, thereby documenting an overlooked period between the fishing rights cases of the turn of the twentieth century and the 1960s and 1970s. Charley left a lasting legacy that scholars have not recognized because many of his visionary ideas came to fruition decades later. Finally, my analysis of Charley's letters also documents personal details that afford readers the unique perspective of one Indigenous person navigated through a tumultuous period in the Pacific Northwest and Native American history.