High-resolution orthoimagery and digital surface models of Green Peter Lake, Oregon, 2023 and 2024

In cooperation with the U.S. Army Corps of Engineers (USACE), the U.S. Geological Survey (USGS) surveyed ground control points and coordinated aerial photograph acquisition of Green Peter Lake, located on the Middle Santiam River about 8 kilometers upstream of the confluence of the Middle Santiam and South Santiam Rivers in western Oregon. Green Peter Lake is a multi-purpose reservoir impounded by the 100-meter ([m]; 327-foot [ft]) tall Green Peter Dam. Aerial photographs were acquired by the Civil Air Patrol (CAP) on December 9, 2023, December 12, 2023, and November 27, 2024, when water levels were at 271, 275, and 254 m (889, 903, and 832 ft; National Geodetic Vertical Datum of 1929 [NGVD 29]) elevation, respectively, below the typical annual “low pool” or minimum-conservation pool elevation of 281 m (922 ft) for flood-risk management operations. Photographs were acquired at consistent altitudes with a WaldoAir XCAM Ultra 50 camera mounted on a Cessna aircraft and captured the entire reservoir area as defined by full pool (or maximum-conservation pool, 308 m [1,010 ft]), including the major streams entering the reservoir, the Middle Santiam River and Quartzville Creek, as well as other smaller tributaries. The USGS applied structure-from-motion (SfM) techniques to these aerial photographs, following the workflow outlined in Over and others (2021) and used for similar datasets (Schwid and others, 2025), and generated three-dimensional xyz point clouds, digital surface models (DSM), and orthomosaics of Green Peter Lake. 
 
This data release includes ground control points, dataset footprints, original aerial photographs, point clouds, DSMs, and orthomosaics of Green Peter Lake with varying aerial extents and resolutions that were developed from imagery acquired in 2023 and 2024: (1) the December 9, 2023 model (GreenPeterLake_20231209) covered the main body of the reservoir and the Quartzville Creek arm but excluded the Middle Santiam River arm; (2) the December 13, 2023 model (GreenPeterLake_20231213) covered the main body of the reservoir and the Middle Santiam River arm but excluded the Quartzville Creek arm; (3) the November 27, 2024 model (GreenPeterLake_20241127) covered the entire reservoir area. 
 
This documentation describes a CSV file containing ground control point locations surveyed in 2023 and 2024, that were used to spatially register SfM datasets and a polygon shapefile including the footprints (spatial coverage) of the DSMs and orthomosaics.

 
References:
Over, J.R., Ritchie, A.C., Kranenburg, C.J., Brown, J.A., Buscombe, D., Noble, T., Sherwood, C.R., Warrick, J.A., and Wernette, P.A., 2021, Processing coastal imagery with Agisoft Metashape Professional Edition, version 1.6—Structure from motion workflow documentation: U.S. Geological Survey Open-File Report 2021–1039, 46 p., accessed March 11, 2026, at https://doi.org/10.3133/ofr20211039.
 
Schwid, M.F., Keith, M.K., and Overstreet, B.T., 2025, High-resolution orthoimagery and digital surface models of Fern Ridge Lake, Oregon, during annual low pool, January and February, 2023: U.S. Geological Survey data release, accessed March 11, 2026, at https://doi.org/10.5066/P1Q5K657