Relatives say a man whose skeletal remains were found near Interstate 70 in Columbia was a veteran and 9/11 first responder who had been missing for about a month.

The Columbia Missourian reports that hikers found the remains of 39-year-old Glen Lester O’Neal on Thursday.

O’Neal’s brother-in-law, Gregory Silvey, said Monday that a missing person report was filed around the end of June or beginning of July. He described O’Neal as an “energetic person” who “seemed to love life.” He says he doesn’t know when or how O’Neal died.

Police have not identified a cause of death, and the investigation is ongoing.