The cause of the fire is still under investigation. Utility officials found no downed power lines around where the fire broke out.
ADVERTISEMENTUS Colorado Governor Jared Polis toured destroyed neighbourhoods in Boulder County on Sunday as he witnessed first-hand the devastation caused by last week's massive wildfire, which destroyed nearly 1,000 homes and other buildings.
Flames ripped through at least 24 square kilometres in suburbs between Denver and Boulder.
Authorities initially said everyone was accounted for after the fire. But Boulder County spokesperson Jennifer Churchill said the reports of three people missing were later discovered amid the scramble to manage the emergency.
One was found alive, officials said Sunday.
Search teams are still looking for the two missing people in the snow-covered but still smouldering debris of the massive wildfire, while people who barely escaped the flames sorted through what was left after the blaze and investigators tried to determine its cause.
The wildfire came unusually late in the year following an extremely dry fall and amid a winter nearly devoid of snow. Experts say those conditions, along with high winds, helped the fire spread.
"I know this is a hard time in your life if you've lost everything or you don't even know what you lost," Polis said after the tour.
"A few days ago, you were celebrating Christmas at home and hanging your stockings and now home and hearth have been destroyed."
The cause of the fire is still under investigation. Utility officials found no downed power lines around where the fire broke out.
Boulder County Sheriff Joe Pelle said on Saturday that authorities were pursuing a number of tips and had executed a search warrant at "one particular location". He declined to give details.
Of at least 991 buildings destroyed by the fire, most were homes, but the blaze also burned through eight businesses at a shopping centre in Louisville, including a nail salon and a Subway restaurant.
In neighbouring Superior, 12 businesses were damaged, including a Target, Chuck E. Cheese, a Tesla dealership, a hotel, and the town hall.
The two towns are about 30 kilometres northwest of Denver, with a combined population of 34,000.
Utility crews expected to get most electricity restored to the homes still standing Sunday but warned gas service might take longer to get back.