"We will, eventually, find them," Dayton added. "Until then, we will always have our memories of them. Nothing changes that."
However, a small number of the pilot Dale Smith's family, who also was flying his son Daniel Smith and wife Sheree Smith in the aircraft, remained in Idaho as of Tuesday afternoon, according to a Smith family friend, Nadine Bird of San Jose, Calif.
"The Smith family has not given up," she said, while acknowledging that the official search effort, and that by members of the Norton family, had ceased on the ground.
On behalf of the Smith family which continued to be unreachable for direct comment Bird and others friends have set up the Search for Dale's Plane website as the search largely shifted to a review of satellite images of the wild region.
A private plane also has been hired by the family to fly over the area.
Meanwhile, the Valley County Sheriff's Office said it would continue to offer what aid it can, albeit at a much scaled back level and depending on any developments.
Bird also told The Salt Lake Tribune that Cascade and Yellow Pine, Idaho, Mormon church members have been helping with meals and accommodations for searchers over the past week and a half.
The official search, involving search and rescue crews and aircraft from multiple county, state and military agencies, had ended last Friday. Authorities then had noted their extensive, albeit unsuccessful efforts, over a week's time to find any trace of the wreckage of passengers and the danger that deep and continuing snowfall, sub-zero temperatures and the treacherous terrain posed to personnel.
On Tuesday, Dayton said family and friends who had focused on a 9-square-mile area of deep ravines, ragged ridgelines and thick forests about 100 miles northeast of Boise reluctantly came to the same conclusion.
Dayton said searchers have been gathering daily at dawn or earlier, in the tiny town of Cascade, Idaho, and then driving about 50 miles to the search area near the Frank Church-River of No Return Wilderness.
"That's three hours' driving, all on mountain roads, and once you are there you still have to have all the right gear. Then you find the ridgeline and start hiking, trying to spot one teeny speck [of wreckage] out of a gigantic area," he said.
The families of the missing were discouraged when the official search effort wrapped up late last week, Dayton acknowledged.
"Now, we have a better perspective on how the local sheriff didn't seem to be too encouraging," he added. "It's too rough terrain. The worst thing you can do is have someone who's helping to search for these people to get in trouble themselves."
The plane was en route from Baker City, Ore., to Butte, Mont., when it went down.
Jonathon Norton grew up in Salt Lake City and was a senior at BYU-Idaho, along with Amber Smith. They had planned to be married on Jan. 4.