The first long-distance electric power transmission line in the United States is completed, running 14 miles (23 km) between a generator at Willamette Falls and downtown Portland, Oregon.

Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a transmission network. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid.

The Willamette River is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is 187 miles (301 km) long, lying entirely in northwestern Oregon in the United States. Flowing northward between the Oregon Coast Range and the Cascade Range, the river and its tributaries form the Willamette Valley, a basin that contains two-thirds of Oregon's population, including the state capital, Salem, and the state's largest city, Portland, which surrounds the Willamette's mouth at the Columbia.

Portland is the most populous city in the U.S. state of Oregon. Located in the Pacific Northwest at the confluence of the Willamette and Columbia rivers, it is the 28th-most populous city in the United States, sixth most populous on the West Coast, and third most populous in the Pacific Northwest with a population of 652,503 at the 2020 census, while the Portland metropolitan area with over 2.54 million residents is the 26th-largest metropolitan area in the nation. Almost half of Oregon's population resides within the Portland metro area. It is the county seat of Multnomah County, Oregon's most populous county.