U.S. Sen. Dan Sullivan of Alaska wants top officials in the Interior Department to hand over texts, emails and other communication they’ve had with conservation groups.

Sullivan made the request in a four-page letter to Tracy Stone-Manning, director of the Bureau of Land Management, this week.

Sullivan told reporters Tuesday that he wants to know why the Bureau of Land Management has dropped an effort to open the door for the federal government to convey the land beneath the 800-mile trans-Alaska pipeline to the state.

He said he’s concerned the agency’s lack of action comes in response to conservation groups who have filed a petition with the Interior Department calling for a plan for the decommissioning of the 47-year-old pipeline.

Earlier this summer, Stone-Manning abandoned a process to lift a land order that would have enabled the conveyance of the land to the state, Sullivan said in the letter.

“Your decision to abruptly abandon the public process associated with lifting (Public Land Order) 5150, without notice, at the same time that far-left environmental groups are trying to shut down the Trans-Alaska Pipeline System (TAPS) raises questions regarding potential collusion between the Biden Administration and the Lower-48 radical environmentalists that want to shut down Alaska,” Sullivan writes.

[Previously: Environmentalists urge US to plan ‘phasedown’ of trans-Alaska pipeline amid climate concerns]

The Bureau of Land Management in Alaska did not respond to requests for comment Wednesday. Officials with the Interior Department, which oversees BLM, declined to comment Wednesday.

“We don’t respond to congressional letters through the media,” Interior spokesperson Melissa Schwartz said in an email.

U.S. Sen. Lisa Murkowski, a member of the Senate Energy and Natural Resources Committee, also pressed Stone-Manning in June about the agency’s inaction on the revocation of the land order, at a committee hearing.

Stone-Manning cited a busy workload as the reason for the delay.

Groups such as Sovereign Iñupiat for a Living Arctic, the Center for Biological Diversity and Alaska Community Action on Toxics submitted the petition in June to the Interior Department. They asked for a “managed phasedown” of the pipeline, along with a supplemental environmental review.

The groups said a supplemental analysis should consider new information, including a review of oil’s impact on global warming and a proper examination of vulnerable wildlife such as polar bears, they said.

Since 1974, the Bureau of Land Management has granted two, 30-year right-of-way approvals for the pipeline system. The current one is set to expire in 2034.

The pipeline today delivers a fraction of the crude oil it did in the 1980s. But revenue from the oil remains vital to state operations. The pipeline is expected to carry more oil in the coming years as large, new fields begin production, including ConocoPhillips’ Willow field.

Sullivan told reporters on Tuesday that the potential dismantling of the pipeline might seem unlikely, but it “should scare every single Alaskan.”

Sullivan is asking the agency for all communications on the matter between Interior Department officials and third parties, starting in 2021, according to the letter. He’s seeking text messages, Microsoft Teams chats, telephone call logs and other records. He wants them by Sept. 13.

Public Land Order 5150 was issued in 1971. It established a utility and transportation corridor along the pipeline route and made the lands unavailable for selection by the state.

Sullivan spoke at the Anchorage offices of the Alaska Oil and Gas Association, during a press conference organized by Gov. Mike Dunleavy to highlight actions by the Biden administration that limit resource development in Alaska.

Three Republican members of the House Committee on Natural Resources also criticized the Biden administration’s policies on resource development. U.S. Reps. Pete Stauber of Minnesota, Russ Fulcher of Idaho and Tom Tiffany of Wisconsin are visiting Alaska for a tour of the North Slope this week.