(CNN) -- Calm weather Saturday aided the containment effort against a large wildfire that encroached into Boulder, Colorado.
"We have really favorable weather," said Bob Summerfield, a spokesman for the team battling the blaze. "We haven't fully eliminated the threat."
The team expects to fully contain the Fourmile Canyon fire late Monday or Tuesday. Dry weather is expected, with light winds forecast.
More than 1,000 firefighters from several states have strengthened their lines and are tackling hot spots, Summerfield added.
The fire, which started Monday morning, has charred more than 6,400 acres of countryside and destroyed 172 structures -- 160 of which were homes -- on Boulder's west side. It was 73 percent contained Saturday night.
Terry Krasko, a spokesman for the team battling the blaze, said the cost of the firefighting effort so far was $6.7 million.
Boulder County Sheriff's Cmdr. Rick Brough said authorities were preparing to open the "burn area" to residents, but no date had been set.
Utility companies are restoring service to areas where residents have returned, Summerfield said.
Boulder is about 35 miles northwest of Denver, at the eastern edge of the Rocky Mountains.
Colorado Gov. Bill Ritter declared a state of emergency this week, throwing $5 million into the battle to save homes and forests in the canyon. The cause of the fire is under investigation.
CNN's Phil Gast contributed to this report.