Support of the United States’ navigation needs is one of the Army Corps of Engineers’ earliest civil works missions dating back to 1824. The U.S. Congress, recognizing the importance of the Columbia and Willamette rivers to the economy of the Northwest, established the Portland District in 1871. One of the original goals of the District was to remove obstacles to navigation in the two rivers. Today, the region’s commercial development is still dependent on safe passage of sea-going ships across the bars and up the waterways. The Portland Corps of Engineers keeps Oregon's waterways safe and navigable through dredging sandbars and channel deepening, ensuring safe transport for more than $18 billion in waterborne commerce.