An official leading the search for a missing Colorado woman urged her fiance to speak with investigators, saying Friday that police believe he is the last person to see the 29-year-old "face to face" since Thanksgiving.

Police also began searching the property of Kelsey Berreth's fiance, Patrick Frazee. Officials said completing the search could take days and did not immediately disclose any information about why they were combing the property in the tiny community of Florissant, south of Denver.

The investigation and length of time Berreth has been gone suggest her disappearance is suspicious, said Miles De Young, police chief of Woodland Park, the city where Berreth lives that's about a 20-minute drive from Florissant.

He said police are "considering every possibility" but have declined to call Frazee a suspect or person of interest. De Young said Frazee has communicated with police through his attorney but wants him to speak directly with investigators because police believe he was the last person to see Berreth, whose disappearance has mystified her family and authorities.

She was last seen on surveillance video entering a grocery store on Thanksgiving Day with what appears to be her 1-year-old daughter in a baby carrier. Frazee told police that the couple met sometime that afternoon so he could pick up the child. They did not live together, and the girl now is staying with her father.

Police said the only sign of Berreth, a pilot who works as a flight instructor for an aviation company, after that were some text messages from her cellphone. Location data later suggested that by Nov. 25 the phone was in Idaho, 800 miles (1,290 kilometers) from Berreth's home.

Public records show that property associated with Frazee's name in Florissant covers 35 acres. De Young would not comment on what evidence police presented to a judge to get a search warrant.

The FBI and other agencies were helping with the search.

Frazee's attorney, Jeremy Loew, said his client is cooperating with the investigation and was not asked to participate in the property search.

"We encourage law enforcement to take whatever steps it deems necessary to find Kelsey Berreth and to be able to exclude Patrick Frazee as a possible suspect in this missing person investigation," Loew said in a statement.

Loew previously said his client provided police with DNA samples and access to his cellphone. Frazee told police that Berreth last texted him on Nov. 25, the Sunday after Thanksgiving.

Her employer, Doss Aviation, received a text message from her cellphone that day saying she planned to take the following week off.

A police investigation was opened Dec. 2 after Berreth's mother asked for a welfare check. Police said they found both of Berreth's cars outside her home.

Police also said Doss Aviation has accounted for all their planes and there's no reason to believe she used someone else's plane for a flight.