Underwater passive acoustic monitoring was conducted at multiple sites on rivers in the Willamette River Basin, Oregon. Hydrophones were used to record the sound associated with coarse river-bed sediment (bedload) movement. Bedload supply and transport are key factors determining channel morphology in gravel-bed rivers and can affect reach-scale conditions such as aggradation and incision as well as the formation of smaller-scale channel landforms such as gravel bars and riffles. Bedload transport also has implications for aquatic species that depend upon river-bed sediment, such as macroinvertebrates that dwell in the riverbed and Endangered Species Act (ESA)-listed salmonids that require suitable size substrates for spawning. Therefore, relating bedload transport to streamflow is important for understanding hydrogeomorphic and habitat responses to streamflows, and can be used to inform ecologically sustainable river management decisions (such as environmental flow and river restoration programs), particularly in reaches downstream of dams with altered streamflow and sediment regimes. This data release includes a subset of audio files, in Free Lossless Audio Codec (FLAC) format, collected at three sites on the North Santiam River (Greens Bridge, Mehama, and above Stout Creek) and two sites on the McKenzie River (Walterville and Berggren Watershed Conservation Area). Audio files were recorded for 1 minute every 15 or 30 minutes from 2021 to 2024, generally between November and May of each year. These raw audio files are provided as-is and may contain channel-specific recording errors. Subject to additional quality assurance and control and analysis, these audio files may be useful as a bedload surrogate. The raw audio files published in this data release were collected to inform the Willamette Basin Sustainable Rivers Program (SRP), a partnership between The Nature Conservancy (TNC) and U.S. Army Corps of Engineers (USACE) to provide ecologically sustainable flows downstream of dams while still meeting human needs and congressionally authorized purposes. This documentation describes a subset of the hydrophone audio files collected in 2022-2024 for the Mehama site along the North Santiam River, Oregon. The files are separated by water year in two zipped folders for December 12, 2022 to March 13, 2023, and November 04, 2023 to May 6, 2024. Folder names denote water year acquired, river, and monitoring site (HydrophoneAudio_WYYYYY_River_Site.zip). File names within zipped folders denote site name and timestamp (in Pacific Standard Time) in Month, Day, Year-Hours, Minutes, Seconds format (SiteName_MMDDYY-HHMMSS.flac). This site was collocated with USGS streamgage 14183000 - North Santiam River at Mehama, Oregon; audio included here were collected at flows above 3,580 cubic feet per second at this streamgage. Also included is a photograph of the hydrophones installed at this site.