Unified Police Lt. Justin Hoyal said a couple of hikers discovered the body in a creek bed in a snow-packed area at about 6:15 p.m.
Winder said it appears Helland slipped and fell some distance down an incline, possibly while holding his dog.
Winder called it a "very rugged area."
The cause of Helland's death will not be known until an autopsy has been performed, Winder said, adding: "Based on the condition [of the body], it's likely he was there from Wednesday on."
Winder said Neffs Canyon was one of the few places in the area that was not combed by official search parties during the past week because they didn't think he would have gone that far up into the mountains.
Helland's grandchildren, however, hiked the canyon on Saturday, recalling that it was an area where Helland and his now-deceased wife used to go together.
Winder said the grandchildren did not find the man at that time because his body had been covered by snow that fell the day after he disappeared.
Helland had struggled with short-term memory loss but previously had no trouble finding his way back to his Millcreek-area home, according to family members, who reported him missing on Friday after he hadn't been heard from in two days.
Winder said Helland's family was "grateful for the closure" brought by finding his body.
He said they also expressed gratitude to the hundreds of volunteers who turned out to search for Helland.
On Sunday, more than 1,200 volunteers were part of a massive search party organized by Unified Police
"The [family's] anxiety to locate him was made fathomable by the community's support," Winder said.
The Neffs Canyon trailhead is located at approximately 4300 South and 4300 East, which is about two mile southeast of Helland's home.