A U.S. Border Patrol agent remains at a Bangor hospital after he was injured in an ATV crash in a remote area in western Maine.

The agent, who was not identified, was riding an ATV on Monday afternoon in Gorham Gore, a small unorganized township in northern Franklin County along the Quebec border, when the vehicle crashed, ejecting him, U.S. Customs and Border Protection said Tuesday evening.

The agent’s partner, who was riding a separate ATV, called for help and stabilized his partner’s injuries. Despite the remoteness of their location, first responders arrived within an hour from Jackman, Customs and Border Protection said. Other responders came from the Rangeley Border Patrol Station.

The injured agent was taken to a waiting ambulance that brought him to the Jackman Health Clinic, where he was evaluated before being airlifted to Northern Light Eastern Maine Medical Center in Bangor, where he remains hospitalized.

“Responding to assistance calls is something we do on a regular basis,” said Jason D. Owens, the chief border patrol agent in Maine. “When it hits so close to home, when one of our own agents is the injured party, it really makes us thankful for the training, equipment we have available and for the first-rate response from our local partners who respond quickly to calls for assistance.”

Customs and Border Protection said the agent was wearing a helmet when the ATV crashed.

No cause has been released for the crash, which remains under investigation.