High Quality Content by WIKIPEDIA articles! On October 16, 1805, the Lewis and Clark Expedition camped in the Pasco area, at a site now commemorated by Sacagawea State Park. The area was frequented by fur trappers and gold traders. In the 1880s, the Northern Pacific Railway was built near the Columbia River, bringing many settlers to the area. Pasco was officially incorporated on September 3, 1891. It was named by Virgil Bogue, a construction engineer for the Northern Pacific Railway after Cerro de Pasco, a city in the Peruvian Andes, where he had helped build a railroad. In its early years, it was a small railroad town, but the completion of the Grand Coulee Dam in 1941 brought irrigation and agriculture to the area.