Brian Passey

USA TODAY

ZION NATIONAL PARK, Utah — A growing number of national parks are taking steps to prohibit the use of drones on park property, a move that has some drone users concerned.

A recent incident here in which an unmanned aerial system was seen separating several young bighorn sheep from adults in the herd spurred park officials to make it clear their use is illegal.

"If the young can't find their way back to their parents they could actually die," said Aly Baltrus, chief of interpretation for Zion National Park in Utah.

Baltrus said that incident was only the most recent issue of the private use of drones. Rangers regularly report one to four drone sightings per week, she said.

Both Zion and Grand Canyon National Park have gone through the process of reviewing the use of unmanned aircraft in their respective parks and have officially banned their use, said Jeffrey Olson, spokesman for the National Park Service.

While there are not yet specific regulations regarding drones for all U.S. National Parks Service properties, use of drones at a park is considered a "new recreational use" and as such is not allowed under existing policy, Olson said, adding that the park service expects to issue guidance to all park superintendents in the near future.

Jim Bowers, an artist and drone pilot from Colfax, Calif., says he has used his unmanned aerial system to create videos of various national parks, including Yosemite, for his YouTube channel, Demunseed. He said the park regulations are unfair to artists.

"I'm creating artwork and trying to document the beauty and majesty of that nature for people around the world who might not ever get to see it," said Bowers. "They're obviously using this rule to keep us grounded."

He called the regulations "gray areas" because they were written for full-size aircraft rather than drones or radio-controlled models.

Yet he also said he understands some of the concerns held by park officials and would not want to adversely affect the experience of others visiting the park or disturb wildlife. While there are some "bad apples" among drone pilots, Bowers said most of them are responsible and would not approach wildlife.

"There are good drones and there are bad drones," he said, adding that he is director of a group that uses drones to assist with search and rescue missions.

California's Yosemite National Park is the latest to make it clear drones are not allowed. On May 2, park officials issued an advisory to visitors that drones are prohibited within that park's boundaries.

Dana Soehn, spokeswoman for Great Smoky Mountains National Park on the border of Tennessee and North Carolina, said her park has the same interpretation of the rule Yosemite is using to ban drone flights in the park.

"We have to be very concerned about that visitor experience in some of these more crowded areas," she said.

In Zion, visitors have complained about feeling unsafe as drones buzzed through slot canyons and flew over their heads along the precipitous Angels Landing Trail, where hikers hold tight to chains while ascending a ridge with long drops on both sides. There are additional regulations concerning drone flights in Zion because 84% of the park is designated as wilderness.

The wilderness designation also affects Yellowstone National Park, which has many areas where mechanical use is prohibited, said park spokesman Al Nash. Nash said Yellowstone already has a regulation that prohibits the landing of any kind of aerial vehicle in the park without the park's permission, he said.

Nash added there have been requests to use unmanned aerial systems in conjunction with film permits in the park and those requests have been denied.

"There's ongoing discussion much broader than Yellowstone about the status of unmanned aerial systems," Nash said.

The National Park Service has used unmanned aircraft on a limited official basis for remote research projects in Hawaii's Haleakala National Park, Washington's Olympic National Park and California's Mojave National Preserve, Olson said. Unmanned aircraft also were used to monitor a fire in Yosemite last year.

While Bowers understands the various concerns held by park officials, he does not think outright bans are the way to go.

"I don't agree with them banning the flights completely, only because they're missing the great opportunity to document the area, the wildlife, the park itself, from a whole new perspective," he said.

Passey also reports for The (St. George, Utah) Spectrum