The nations only elected regional government which covers the Portland metropolitan area in Oregon was established in 1979. The three counties that Metro encompasses are Clackamas, Multnomah, and Washington. This area includes 1.3 million residents, 24 individual cities, and ~460 square miles of urban land. The main function of Metro is urban planning for the entire Portland area generally through land-use regulation and transportation planning. One of Metro's first duties was to setup an urban growth boundry that would prevent the Portland area from growing too large, thus becoming unlivable. This really doesn't help much because they just keep extending the urban growth boundries once we reach them.
Other functions of Metro include managing regional parks and greenspaces and the Oregon Zoo. Metro also oversees the operation of the Oregon Convention Center, the Portland Center for Performing Arts, and the Portland Expo Center.