CODY, WYO. — Officials are considering whether to use a manned helicopter flight to try and locate a drone that has crashed into the largest hot spring in Yellowstone National Park.

Several eyewitnesses watched Saturday as a small drone aircraft crashed and sank into Grand Prismatic Spring, park spokesman Al Nash said.

Nash said that he did not yet have full details of the incident, but that it happened as a tourist or group of people may have been attempting to capture aerial photos or video of the picturesque spring in the Midway Geyser Basin.

Park officials have had contact with the parties involved, Nash said, and no charges have been filed, although the incident remains under investigation.

National Park Service regulations prohibit the use of unmanned aircraft within park borders, and Yellowstone has long had strict rules against dropping items into thermal features.

“The idea of people putting foreign objects in hot springs is not new, but this is certainly a new wrinkle,” Nash said.

Early visitors to Yellowstone deposited a wide range of objects into geysers, hot springs and fumaroles. More than a century ago, tour guides would pour soap into geysers as a way of speeding up the natural reactions that resulted in an eruption.

Handkerchief Pool, a once-popular attraction near Old Faithful, got its name because early visitors would toss handkerchiefs into the spring. The items would disappear into the pool’s depths, but eventually emerge later, much cleaner from the hot water. Handkerchief Pool was damaged by accumulated debris, and eventually became dormant.

Nash said park officials are concerned about whether the sunken drone might harm Grand Prismatic Spring, a favorite tourist attraction due to its size and wide range of intense colors.

The pool’s striated colors are the result of various forms of microbial organisms residing in different temperature zones within the hot spring, which ranges from 200–330 feet in diameter and is more than 120 feet deep.

A leaky battery or rusting components might be harmful to microbial life. But locating and removing the drone might also disrupt the hot spring, Nash said, so officials are considering a range of factors. They have yet to locate the drone, which is not visible from the boardwalk along the spring.

Using a helicopter to fly over the spring in search for the drone is one option under consideration.

Nash said Saturday’s incident is only the second serious problem with drones in Yellowstone. Another one crashed into Yellowstone Lake at Grant Marina a few weeks ago, but was recovered.

Nash said he had heard of a drone being used for fire surveillance in or near Yosemite National Park, but the Park Service has not used drones in Yellowstone.

The park’s fall newsletter will include a notice about the prohibition on drones, and public affairs staff will be taking to social media networks to remind visitors of the ban, Nash said.

“The issue of unmanned aircraft in national parks is a fairly recent phenomenon,” he said. “This is still very uncharted territory.”

Contact Ruffin Prevost at 307-213-9818 or ruffin@yellowstonegate.com.