Petroleum and environmental groups are at odds over what’s getting in the way of more drilling for oil and natural gas in the West: too much government regulation or the petroleum industry’s own speculative practices.

The Western Energy Alliance said onshore oil and gas production in the U.S. is projected to exceed energy imports from Saudi Arabia, Iraq, Kuwait, Venezuela, Colombia, Algeria, Nigeria and Russia combined by 2020. Yet federal oil and gas reserves beneath public lands in the West have proven more expensive to develop than deposits in other regions because of excessive government regulation, the group said in a recent report.

The Wilderness Society countered in its own report Wednesday that environmental regulation isn’t getting in the way of oil and gas drilling so much as the companies themselves when they choose not to drill on a large share of the 41 million acres of U.S. Bureau of Land Management land they have leased for development in the West.