HOUSTON (Reuters) - Energy companies in Colorado are spending millions of dollars to derail a push by environmentalists to put measures on November’s ballot that would stifle oil and gas drilling in the state, according to a Reuters review of campaign finance records.

An oil well is seen near Denver, Colorado February 2, 2015. REUTERS/Rick Wilking

Environmental groups are now gathering signatures for two statewide initiatives that would transfer regulatory control of oil and gas development to local governments and create more stringent setback requirements to keep oil and gas activities away from occupied structures.

The state’s Supreme Court this year struck down fracking bans approved by voters in the cities of Fort Collins and Longmont.

A study by the Colorado Oil and Gas Conservation Commission, a state agency tasked with encouraging energy development, found that 90 percent of the surface acreage in Colorado would be unavailable for oil and gas development under the new setback laws, which would require all new development facilities to be 2,500 feet from occupied structures and areas of interest, such as parks.

In the last three months alone, energy companies including Anadarko Petroleum Corp, Noble Energy and Whiting Petroleum, have together donated more than $6.7 million to Protect Colorado, a industry-backed coalition fighting the initiatives, according to a Reuters analysis of campaign finance disclosures.

The heavy spending comes despite a severe crash in oil and gas prices that has forced many energy companies to slash jobs, dividends and investments.

Opponents of the proposed ballot initiatives say they would have a calamitous impact on Colorado, which is the country’s seventh-largest oil and gas producing state, with vast untapped fields.

Anadarko Petroleum since early April has donated nearly $3 million to the group, bringing its total aggregate contribution to more than $4 million.

A spokesman for the company said the initiative would be “devastating for Colorado.”

Noble Energy donated $2.5 million to Protect Colorado at the end of April. Noble said the initiatives would harm the economy and cause job losses, and reduce funds for schools and other public services.

In June, Bayswater Exploration and Production, DCP Midstream, an affiliate of Phillips 66, Synergy Resources Corp and Whiting Petroleum Corp gave a combined $785,000 to Protect Colorado. Independent producer PDC Energy has given more than $1 million to the organization since it registered as an issue committee in 2014.

The initiatives each need 98,492 signatures collected by Aug. 8 to qualify for the November ballot.

Todd Ely, on the faculty of the School of Public Affairs at the University of Colorado Denver, said there is no limit on donations the companies can make because the coalition formed around an issue.

“The outcome is critical to existing and future investments in Colorado and elsewhere, especially for a cyclical industry,” he said.

Coloradans Resisting Extreme Energy Development, among the groups collecting signatures, declined to comment on the number gathered thus far. But Lisa Trope of Food & Water Watch said she was optimistic the measures would get on the ballot.