NCF-Envirothon is an annual environmentally themed academic competition for high school aged students organized by the NCF-Envirothon a program of the National Conservation Foundation. The competition is held by the United States and Canada on a regional, state, and bi-national level. Envirothon combines in-class and hands-on environmental education in a competition setting which involves a problem-solving presentation as well as written field tests. The competition tests students on five core subjects- aquatic ecology, forestry, soils and land use, wildlife- along with a fifth annually-changing subtopic which focuses on relevant environmental issues. Currently, roughly 500,000 students from forty-five U.S. states and nine Canadian provinces/territories participate in the competition.