Two national park advocacy groups predict catastrophic consequences for Grand Teton and Yellowstone national parks if congressional lawmakers fail to compromise to avoid the “fiscal cliff.”

Seasonal employees, such as climbing and rescue rangers, trail crews and maintenance workers, would bear the brunt of a fiscal-cliff sequester, said the National Parks Conservation Association and Coalition of National Park Retirees. The visitor experience would ultimately suffer, the groups say.

But the park doesn’t consider seasonal employees dispensable, Grand Teton spokeswoman Jackie Skaggs said.

“Some of those positions we couldn’t operate the park without,” she said.

National media are reporting that congressional lawmakers are inching closer to a year-end deal that would avert plunging over the fiscal cliff. Failure to reach a compromise would trigger $1.2 trillion in cuts to discretional spending, a budget scenario known as sequestration.

Included in the cuts would be $190 million out of the National Park Service’s budget, according to the National Parks Conservation Association. That’s 8.3 percent of the service’s budget.

“It would be deeply damaging to the Park Service and unprecedented in scope,” John Garder, the group’s budget and appropriations legislative representative, said in a telephone interview from Washington, D.C. “The cut is estimated at 8.3 percent. However the cut would need to been absorbed over the last three quarters of the year, so in reality the cut would be more than 10 percent.”

The $190 million out of the budget is equivalent to 9,000 seasonal rangers and another $40 million, said Joan Anzelmo, a Jackson Hole resident and a member of the executive council for the Coalition of National Park Retirees. Eliminating seasonal employees would be the “easiest cost-cutting measure,” she said.

Deny Galvin, a former two-time deputy director of the Park Service who’s associated with both park advocacy groups, agreed.

“If I were a park superintendent and someone said, ‘You have to take an 8.3 percent cut,’ I’d be looking at seasonals,” Galvin said in a telephone interview. “The logic all points to reducing seasonals. And of course, if you reduce seasonal, you reduce visitor services.”

Because most parks have “75 to 90 percent” of their funding locked up in fixed costs such as permanent salaries and electricity, there’s little flexibility when slashing budgets, Galvin said.

In Grand Teton, 82 percent of the $12.6 million base budget allocation goes toward permanent employee salaries and other fixed costs. Another $4.8 million comes in, but it cannot be used for operations, Grand Teton spokeswoman Jackie Skaggs said.

“Grand Teton National Park looks at it like 92 percent fixed to 8 percent not.”

The park considers its seasonal employees — who eat up another 10 percent of the base budget — a fixed cost, and not a viable option to be cut, Skaggs said.