Kelly Daniel Minoza, 44, was last seen in Hay River on a red ATV at 4 p.m. on May 14.
He is described as being five foot nine inches tall, weighing 150 pounds with a medium build.
He was also wearing multi-colored track pants and a grey hoodie.
Kátł’odeeche Chief April Martel confirms that Minoza has also not registered at any of the evacuation centres.
“Kelly is a very shy man and please be calm when approaching him. Please be nice to him and has a heart of gold,” reads a post to social media.
“We are very concerned for his well-being,” she adds.
Anyone with information on Minoza is asked to call the Hay River RCMP detachment at 867-874-1111.