The 82 people who remained on the list Friday were all from Larimer County in the Rocky Mountain foothills.
Authorities said they could be hermits living alone in the upper reaches of canyons, or people who chose to stay behind and don't know they were reported missing.
And as the names on the lists dwindle, the ones that remain are increasingly likely to be people actually missing, injured or dead.
"We recognize that as we start getting down to the nitty-gritty that some of these people are going to be missing and perhaps dead, but until we get everybody out that we're aware of and all of the lists are cross-checked, we're not ready to focus on that yet," Larimer County sheriff's spokesman John Schulz said.
The lists were compiled primarily from calls from families and evacuees who said they couldn't locate their loved ones or neighbors. In most cases, those people made contact with their families or authorities to say they were safe.
The number of confirmed deaths stood at seven, with three people missing and presumed dead.
Pinpoint searches were underway of individual homes, vehicles and piles of debris. In Boulder County, where the number of people unaccounted for had dropped to zero, searchers were scouring isolated areas for people who may not have been on any of the lists.
"I think what we're looking at is those people who maybe were reclusive or lived in the mountains by themselves," Boulder County sheriff's spokesman Rick Brough said. "They might be the ones we still need to check on, but I don't expect the numbers to be large at all."