Grand Teton National Park could be forced to close three of its six visitor centers during the busy summer tourist rush.

In Yellowstone National Park, the west, south, east and northeast entrances might not open until two to four weeks later than usual.

Those scenarios will become reality if congressional leaders fail to reach a budget agreement before March 1, according to the Coalition of National Park Service Retirees.

Earlier this month, Jon Jarvis, the director of the National Park Service, instructed park superintendents to begin planning for “sequestration,” the term that describes the practice of imposing mandatory spending cuts in the federal budget. Sequestration was agreed to almost two years ago to avoid a previous budget train wreck. Battling over the federal budget, deficit spending and the climbing debt have repeatedly left Democrats and Republicans unable to reach a spending compromise that would avoid the sequestration.

The cuts now facing the government would, without a deal between lawmakers, trigger across-the-board 5 percent cuts to Park Service budgets. The cuts would have to be absorbed over the last six months of the fiscal year.

The sequestration plans for Grand Teton, Yellowstone and a handful of other national parks have been leaked to the retirees group, said spokeswoman Joan Anzelmo.

“We have sources, we have friends, and we worked to get that information,” said Anzelmo, a former Grand Teton public affairs spokeswoman. “The Park Service director and superintendents could adjust how they’re going to take the cuts, but this is the best information that we were able to get.”

A sequester would cut Grand Teton’s fiscal year 2013 budget by $627,000.

The plans laid out to make up for the loss in Grand Teton include closing “the Jenny Lake Visitor Center, the Laurence S. Rockefeller Preserve, and the Flagg Ranch Visitor Contact Station for the summer season,” a Coalition of National Park Service Retirees statement said.

The closures, the retirees group estimated, would be felt by more than 300,000 visitors.

To the north, in Yellowstone, officials would be forced to delay spring road openings in order to meet its $1.75 million budget reduction, the retirees group statement said.

Park access from West Yellowstone, Mont., Jackson and Cody would be delayed two to three weeks, the statement said. Access via the Chief Joseph Highway and Beartooth Highway would be delayed three to four weeks.

In interviews, National Park Service officials would not confirm or deny the accuracy of the retiree group’s information.

“There’s been no change to the Department of Interior policy that directs us to refer reporters and their questions about sequestration to the Office of Management and Budget,” Grand Teton spokeswoman Jackie Skaggs said.

The OMB has repeatedly failed in the past to respond to interview requests made by the Jackson Hole News&Guide.

On Wednesday, the Park Service still wouldn’t say what steps it anticipates taking, but did release a statement in response to the retiree group’s leaked information.

“We remain hopeful that Congress is able to avoid these cuts,” said Jeffrey Olson, chief spokesman for the Park Service. “I can confirm, on background, that the impacts outlined in the retirees’ release include potential consequences of a sequester. The planning process is ongoing, and the information contained in the release should not be considered final.”