Butte Oil, also known as Butte Coal Oil or Coal Oil, is a type of crude oil that was historically extracted from coal. It is a byproduct of the coal gasification process, where coal is heated in the absence of oxygen to produce gas, and the remaining liquid is collected as butte oil. This oil has a dark, thick consistency and a strong odor, and it was once widely used as a fuel and a source of kerosene and lubricating oils.

The significance of butte oil in the United States stems from its role in the early development of the country's energy infrastructure. During the 19th and early 20th centuries, butte oil was a crucial component in the production of kerosene, which was the primary lighting fuel before the advent of electricity. The demand for kerosene was high, and butte oil was a cost-effective and readily available resource.

According to historical data, the production of butte oil reached its peak in the late 19th century, with the United States producing approximately 30 million gallons annually. The region of Butte, Montana, became synonymous with the production of butte oil, with the town's economy heavily reliant on this industry. However, as the 20th century progressed, the demand for kerosene decreased with the rise of electricity and the development of more refined petroleum products. This decline led to the eventual decline of butte oil production, with the last commercial butte oil well in the United States being closed in the 1950s.

The environmental impact of butte oil production also played a role in its decline. The process of extracting butte oil from coal was energy-intensive and produced significant amounts of waste, including coal slag and tar. These byproducts posed environmental challenges, further contributing to the industry's downfall.

In summary, butte oil was a significant energy resource in the United States during the late 19th and early 20th centuries, primarily used for the production of kerosene. Its decline was driven by the rise of electricity, the development of more refined petroleum products, and environmental concerns associated with its production.