Editor's note: This updates with reaction from National Parks Conservation Association and U.S. Rep. Raúl M. Grijalva.

Interior Secretary Ryan Zinke moved Tuesday to find a way to boost funding to address the National Park Service's maintenance backlog, proposing to substantially increase park entrance fees during the "high season" for vacations. It's a move that seemingly would do little to address the backlog, estimated at roughly $12 billion, while hitting families with school students hardest.

“Secretary Zinke would rather take money directly out of the pockets of hardworking Americans instead of coming up with a serious budget proposal for the National Park System,” said Rep. Grijalva, an Arizona Democrat. “More than doubling the vehicle entrance fee at Grand Canyon, as this proposal would do, or any other park is not a sustainable funding strategy. We should be encouraging more people to get outdoors and enjoy our great natural wonders instead of discouraging them by raising park entrance fees. Whether it’s healthcare, tax cuts, or now access to our national parks, the Trump administration and Republicans in Congress just don’t seem to care about everyday American families.”

Under the fee proposal laid out in a press release, "entrance fees would be established at 17 national parks. The peak season for each park would be defined as its busiest contiguous five-month period of visitation."

During the peak season, the release explained, a seven-day-long "entrance fee would be $70 per private, non-commercial vehicle, $50 per motorcycle, and $30 per person on bike or foot. A park-specific annual pass for any of the 17 parks would be available for $75."

Parks to be affected by these rates, if approved, are "Arches, Bryce Canyon, Canyonlands, Denali, Glacier, Grand Canyon, Grand Teton, Olympic, Sequoia and Kings Canyon, Yellowstone, Yosemite, and Zion national parks with peak season starting on May 1, 2018; in Acadia, Mount Rainier, Rocky Mountain, and Shenandoah National Parks with peak season starting on June 1, 2018; and in Joshua Tree National Park as soon as practicable in 2018."

“We should not increase fees to such a degree as to make these places – protected for all Americans to experience – unaffordable for some families to visit," said Theresa Pierno, president and CEO of the National Parks Conservation Association. "The solution to our parks’ repair needs cannot and should not be largely shouldered by its visitors.

“The administration just proposed a major cut to the National Park Service budget even as parks struggle with billions of dollars in needed repairs," she added. "If the administration wants to support national parks, it needs to walk the walk and work with Congress to address the maintenance backlog."

If implemented, Interior officials said, the higher fees could be expected to raise $70 million a year. Eighty percent of the revenues raised would remain in the parks where they are collected, with the remainder to be distributed elsewhere in the National Park System.

Not mentioned in the release was how the proposed entrance fees were calculated, or how significant of an impact the additional revenues would have on the maintenance backlog.

“I think the proposal speaks for itself. I don’t think we’re going to speculate on what is a good amount of money, or what is enough," said Park Service spokesman Jeff Olson.

Public comment on the proposal will be open from October 24 to November 23. You can find details on the proposal and leave your comments at this site.

The proposal comes in the wake of the Trump administration's desire to cut the National Park Service budget by roughly $400 million and its staff by about 1,200. It also comes as Interior is raising hundreds of millions of dollars from off-shore oil and gas lease auctions, a source of revenues Mr. Zinke earlier this year said could be used to address the park system's maintenance woes.

But the Interior secretary almost from the start of his tenure at Interior has said entrance fees need to be adjusted upward.

"About half the parks don't charge. Which is interesting," he said during a media call in May. "We have a tier system (for entrance fees). A number of parks chose not even to follow the tier system. So, we're concentrating on where are revenues, and shore it up."

The tiered approach to fees, if enacted, likely would hit hardest families whose vacations are governed largely by school schedules, as school vacations typically coincide with the high seasons outlined by the release. 

This past summer senior citizens, not the appropriations system, were looked to by Congress to raise more money for the Park Service. On August 27 the price for a lifetime senior pass to the parks, which had been just $10 for years, jumped to $80. Park Service officials could not say Tuesday how much revenues were generated by that increase.

Yet to come is a proposal to adjust entrance and permit fees for commercial tour operators. "The proposal would increase entrance fees for commercial operators and standardize commercial use authorization (CUA) requirements for road-based commercial tours, including application and management fees," the Park Service release said. "All CUA fees stay within the collecting park and would fund rehabilitation projects for buildings, facilities, parking lots, roads, and wayside exhibits that would enhance the visitor experience. The fees will also cover the administrative costs of receiving, reviewing, and processing CUA applications and required reports."

Unlike entrance fees for park visitors, any proposed increases in CUAs would take effect following an 18-month implementation window, the Park Service said.