Which executive department would most likely need to approve an oil company's new pipeline?

The executive department most likely to approve an oil company's new pipeline is the Department of the Interior (DOI). This department is responsible for managing federal lands and resources, which includes oil and gas production. Additionally, the Bureau of Land Management (BLM), which operates under the DOI, plays a crucial role in approving permits for pipeline construction on public lands.

Other relevant agencies may include the Environmental Protection Agency (EPA), which evaluates the environmental impact of such pipelines, and the Army Corps of Engineers, which oversees projects that might affect waterways. However, the DOI is generally the primary department involved in the approval process for pipeline construction.