Editor's note: This updates with the National Park Service's tally of vacant positions within the agency, efforts to see that law enforcement rangers and firefighters are exempt from the hiring freeze.

National Park Service officials have been told to stop filling vacant permanent positions throughout the National Park System under the federal hiring freeze President Trump ordered, though it remained unclear Wednesday which, if any, seasonal positions would be granted a waiver from the freeze.

President Trump in a memorandum on Monday called for an immediate hiring freeze to run up to 90 days, at which point he expected the Office of Management and Budget to produce a long-term plan to reduce the federal workforce. But for an agency like the Park Service, which annually hires thousands of seasonal workers, the document didn't spell out how the Service should proceed with those positions.

On Wednesday afternoon a memo sent out to management staff across the National Park System said Park Service officials were continuing to understand the process for obtaining exemptions to the hiring freeze. However, wrote NPS Chief Financial Officer Lena McDowall, what has been determined is that:

• As of noon on January 22, 2017, no existing vacant positions may be filled, and no new positions may be created. Executive departments and agencies should not make any new offers of employment. Department and agency heads may make limited exceptions to ensure national security and public safety, but guidance on that waiver process has not been issued yet.
• An individual who has received a job offer/appointment prior to January 22, 2017, and who has received documentation from the agency that specifies a confirmed start date on or before February 22, 2017, should report to work on that date.
• For individuals who have received a job offer/ appointment prior to January 22, 2017, and who have received documentation from that agency that specifies a confirmed start date after February 22, 2017, we are awaiting additional guidance on the review process to determine whether these individuals should report to duty on the agreed upon start date.
• Hiring for seasonal positions is currently underway. It is still unclear which types of seasonal positions may qualify for a waiver, so with the expectation that at least some exemptions will be granted for these positions and in recognition of the time it takes to hire and on-board seasonals, bureaus and offices should continue their seasonal hiring processes to identify qualified candidates who may be expeditiously selected when a freeze exemption is granted. No new offers of employment may be made until a freeze exemption is granted.
• In addition, hiring processes for permanent wildland fire, law enforcement and other public safety positions should continue to identify qualified candidates. No new offers of employment should be made until a freeze exemption is granted.

According to personnel in the Park Service's Washington, D.C., headquarters, the latest "snapshot" of vacancies across the agency counted 1,731.

"The National Park Service is in coordination with the Office of Personnel Management and Office of Management and Budget on their guidance for implementing the hiring freeze. As with previous hiring freezes, the National Park Service will work with the Administration to ensure that we meet the needs of park visitors across the system," said Park Service chief spokesman Tom Crosson. "We realize that maintaining a full staff of firefighters and law enforcement officers at our parks is important for visitor safety. Therefore, per the provisions in the president’s memorandum, we will work with the Department of the Interior to ensure that personnel responsible for the safety and protection of our visitors and resources are exempt from this hiring freeze."

Park Service officials were in ongoing discussions with Interior Department, Office of Personnel Management, and Office of Management and Budget authorities to determine how seasonal positions would be handled under the freeze.

"Seasonal employees are critical to the National Park Service.  They help parks throughout the system provide quality and safe experiences for our visitors throughout peak visitation periods," said Mr. Crosson. "The NPS typically hires around 10,000 seasonal and other temporary employees throughout the year, with more than 8,000 of those on board during the peak summer visitation period."

One park superintendent, who agreed to discuss the memo anonymously, was optimistic that seasonal hiring would be allowed to go forward once the new administration realized the need for these workers.

"The Washington office is heavily engaged in trying to talk to the right people at Interior and (Office of Personnel Management) so they can explain the situation with seasonals and they are able to resolve that. It will come eventually," the superintendent said. "I’m pretty confident that it actually will get resolved pretty fast. And we will be able to hire seasonals, because seasonals aren’t what this is about. Every time we’ve had a hiring freeze in the past we’ve been able to hire seasonals. ... You can’t operate a Yosemite or a Yellowstone without a seasonal staff to collect the trash and protect the public safety. You just can’t do that, and it would adversely effect the local communities.”

But the superintendent was concerned that the eventual OMB plan might aim to reduce the federal workforce by ordering that once an employee retires that their specific position cannot be filled. If you let folks retire but don’t fill their position, you might lose a very valuable position, the superintendent said, adding that the best solution would be to give the Park Service a set personnel budget and let the agency decide which positions to fill.

At the National Parks Conservation Association, officials were alarmed by the latest developments and hoped the administration would move quickly to allow the Park Service to fill its seasonal needs.

“We’re still trying to figure out what the implications will be, but we are alarmed at the potential for an already understaffed Park Service to be further challenged to handle the great record number of visitors and care for resources that are increasingly falling into disrepair," said John Garder, NPCA's point person for budget and appropriations. "We’re concerned about how long it could take the administration to figure out the details as the hiring season for seasonal park rangers is upon us. Normally the Park Service would be looking to hire about 8,000 seasonal rangers at this time. And we are deeply concerned about whether or not they’ll be able to hire the front line workers of the Park Service, and if so when they might be given permission to do that.”

Last year's unofficial visitation tally for the National Park System was 6.4 percent above the then-record 307.2 million counted in 2015, said Mr. Garder. Some individual parks, though, saw double-digit increases, he said, pointing to Zion National Park, which saw a 17.6 percent increase, to 4,317,028

“If you look at some parks at the (visitation) increase from December '14 to December '16, you’re looking at shocking numbers for some parks. If you’re looking at parks like Zion, Rocky Mountain, it's crazy. These parks are already struggling to accommodate these visitors and do their normal work. The reality is they need more staff, not less," said Mr. Garder.

According to NPCA:

• Based on the latest available data, the National Park Service had more than ten percent fewer staff in Fiscal Year 2015 compared to five years prior.
• A contributor to the growth of the $12 billion park service maintenance backlog has been lack of staff to perform day-to-day maintenance and repair jobs that keep the backlog from growing
• In 2015, NPS only had 58 cents out of every dollar needed just to keep up with the backlog

“Congressman (Ryan) Zinke in his testimony to be the next Interior secretary said very clearly that two of his main priorities are to address the maintenance backlog and to provide the resources that park rangers need," said Mr. Garder. "We’re overjoyed to see that, but this (presidential) memorandum, depending on how it’s implemented, would seriously challenge his commitment to parks, becaue you can’t repair parks without rangers. And they’re certainly not going to have the resources they need to take care of visitors if there are fewer of them out there.

"It’s important to remember that it’s not just the seasonal rangers who are the face of the Park Service to the visitors, it's also the professionals: the scientists, the archaeologists, the cultural resource specialists, the wildlife biologists. These are our national treasures, our cultural and national heritage.”