A 73-year-old man remains missing more than three weeks after authorities found his unoccupied RV at a remote campsite in the Adirondack Mountains of upstate New York, state police said.

Craig K. Streeter, of Mahopac, was last seen on Aug. 2 at a Stewart’s Shop in Indian Lake, according to the New York State Police.

Investigators said Streeter is known to spend brief stretches off the grid, but concern has grown because no one has had contact with him for several weeks.

The search began after New York State Forest Rangers located Streeter’s RV at campsite 36 on Moose River Road in the town of Inlet and found no evidence of recent activity there.

After officials were unable to find the experienced outdoorsman, additional law enforcement agencies were brought in to assist. The multi-agency search remains active, the NYSP said.

Police said that, at this stage, there are no signs of foul play.

He was last seen wearing a dark-colored long-sleeved shirt and jeans before leaving the store in his RV.

Authorities are interested in hearing from anyone who may have encountered Streeter while camping or traveling along Moose River Road or in nearby remote camping areas. Anyone with information is asked to call New York State Police at 518-897-2000.

News Outlet has reached out to the New York State Police for additional information.