Thousand Acres is part of the 1,500 acre natural area at the confluence of the Sandy and Columbia rivers known as the Sandy River Delta in the Columbia River Gorge. The site, owned by the US Forest Service, was historically a dynamic alluvial floodplain with two distributaries of the Sandy River flowing across it and a mosaic of bottomland forests, wetlands and meadows. The site was severely impacted by deforestation, highway and railroad development, hydrology modifications, and cattle grazing. As a result, the floodplain wetland site became disconnected, had poor water quality, and was