Colorado is located in the Western United States and features some of the highest peaks of the Rocky Mountains. Manufacturing, finance, and tourism make up the core of Colorado’s diverse economy. While much of the state’s manufacturing is based on the processing of local raw materials, technology-dependent light manufacturing is also becoming more prevalent. Tourism is a leading component of the state's service sector with skiing, snowboarding, and other winter sports as some of the most visible and popular attractions. Old mining towns such as Aspen, Telluride, and Breckenridge have transformed into world-renowned mountain resorts. Although oil shale is not yet seen as an economically viable source of energy, Colorado holds an estimated 1 trillion barrels if businesses ever pursue the resource.