Colorado Gov. John Hickenlooper and Sen. Michael Bennet have asked the U.S. Bureau of Land Management (BLM) to reduce the size and scope of an oil and gas lease sale scheduled for December in the southwest corner of the state that includes greater sage grouse habitat.

Carefully worked out three years ago by Obama administration between federal agencies and a dozen western states, Hickenlooper was one of several governors from resource-rich states who had embraced a collaborative effort with BLM and others.

HIckenlooper and and Bennet, both Democrats, sent separate letters to acting BLM Colorado Director Gregory Shoop, expressing concerns about the proposed sales and location of some parcels that are within grouse habitat, a contentious focus for the better part of the past decade.

BLM’s proposed lease sale scheduled for Dec. 6 would include 143 parcels and 108,600 acres in priority and general greater sage grouse habitat, which by Hickenlooper’s calculations, represents 62% of all the sale parcels and nearly half (46%) of the total acreage to be offered.

Hickenlooper in July sent a letter regarding the scoping review of the proposed auction, and BLM agreed to remove 17 parcels. In his latest request, the governor said he wanted all 143 objectionable parcels to be removed.

“We explicitly request that you make the recommendation to the BLM Washington, DC, office,” Hickenlooper wrote. He also pointed out that the potential still exists for more than 100,000 acres of habitat being impacted.

BLM removed 17 parcels and about 6,300 acres of grouse-impacted habitat from the lease sale, and Hickenlooper said he was encouraged with the removal of 7,903 acres and several parcels in the North Fork Valley, which include big game winter range and wildlife migration corridors.

Hickenlooper noted that Gunnison County officials and the Colorado Department of Public Health had also weighed in with concerns. “Given the continued local concern, we request that the remaining five parcels in North Fork Valley be deferred from this sale until the draft field office resource management plan is finalized,” he said.

In addition, he reiterated a request that BLM agree to limit the density of surface facilities in those areas to no more than one well pad/mile. The governor also said that he spoken with Interior Secretary Ryan Zinke, who he said assured him that “Colorado’s concerns regarding the lease sale would be addressed.”