There a number of renewable and nonrenewable natural resources that are of great significance to Indiana's economy. The state's nonrenewable resources include gas, oil and coal, and its renewable resources come from its forests and waterways.
The state's oil boom began in the late 19th century with an important discovery of natural gas deposits in Trenton Field. The area later became a hub for crude oil production. Indiana ranked 23rd in crude oil production and 26th in natural gas production as of 2005. Coal is also found in Indiana, with over 30 million tons mined over about 80 years between the mid-19th and early-20th centuries.
The state is home to 35,000 miles of waterways, with most of its rivers and streams belonging to the Mississippi Drain basin. By volume, the Wabash River is the largest non-navigable river in the United States. Indiana's forestland, which covers 20 percent of the state, feeds the timber industry and provides the habitat for native wildlife. Tree species found throughout Indiana include red and white oak, yellow poplar, hickory, and hard maple. Despite its abundant natural resources, the state only ranks number 46 in the country in terms of conservation, with 4 percent of state lands designated as conservation areas.