STEVENSVILLE — Mark Lewing has lived in Stevensville 40 years and loved big trees all his life. He worked for the Department of Natural Resources and Conservation (DNRC) for 29 years and retired as the Hamilton Unit manager. “When I was working they used to circulate the Big Tree Register and I’d say, ‘That’s nice.’ But I’d think, ‘I know a cottonwood that is bigger,’ ” Lewing said. That launched his investigation. “The first biggest champion I got was an American elm in Hamilton,” Lewing said. “That got elm disease and died. Then I found the current champion at the school in Stevensville and the co-champion up the street from it.” While he was working, he had seven champion trees. He retired in 2003 and realized searching for big trees was an interesting hobby.