WESTMINSTER, Colo. -- Authorities investigating the disappearance of a 10-year-old Colorado girl are looking into whether it could be linked to the abduction of a girl in Wyoming as they continue searching land and water near Jessica Ridgeway's home.

Police in the Denver suburb of Westminster are talking with investigators in Cody, Wyo., about 500 miles away, spokesman Trevor Materasso said Wednesday.

A man lured an 11-year-old girl there into a sport utility vehicle Monday saying he needed help finding his puppy. She was released about four hours later and found by hunters. Police there say they're looking for a white man between 55 and 60 years old with short strawberry blond or white hair and a neatly trimmed mustache.

Jessica was last seen Friday after leaving home to meet friends at a park on her way to school.

Two days later, the fifth-grader's backpack was found on a sidewalk in a neighborhood about six miles north of her home. Police won't discuss what was found inside the bag or the results of testing done on it.

Materasso said searchers were scouring Jessica's neighborhood and divers were searching ponds as a "precautionary measure" to see if they can be ruled out as having a connection to Jessica's disappearance. Police also have isolated landfill garbage collected around the time of the girl's disappearance but will search through it only if their investigation points them in that direction, he said.

Police have revealed little about their investigation and have instead tried to keep the focus on Jessica. They've asked the public to study her face in various photos they've released showing her with and without glasses. They're also encouraging people to keep tweeting about her in the hopes that will develop new leads.

On Sunday, a sighting of Jessica in a car with Colorado license plates was reported more than 2,000 miles away in Maine. Dexter, Maine, police Sgt. Alan Grinnell said officers don't know if it really was Jessica spotted in the town of 5,000 people, but authorities have issued a statewide alert for officers to stop a blue Buick station wagon with Colorado plates if they see one. So far, none have been stopped. The car's license plate number isn't known.

Police say Jessica's family has been cooperative, but Materasso said he wouldn't discuss whether they have been ruled out as being involved with the disappearance. He told KOA-AM that investigators are checking out people identified by tips and there are no persons of interest yet.

"We know she's out there, and we want to bring her home," Materasso told the station.

Jessica's mother, Sarah Ridgeway of Westminster, and her father, Jeremiah Bryant of Independence, Mo., issued their first public call for help finding their daughter in a television interview Tuesday.

"I want her to come walking back through that door," Sarah Ridgeway told KUSA-TV in Denver. "I need her to come walking back through that door."

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  • Missing School Girl

    This image provided by the Westminster Colorado Police Department shows 10-year-old Jessica Ridgeway. Police in Westminster are looking for a 10-year-old girl who was last seen walking to school. Jessica Ridgeway normally meets a friend at a park on her way to Witt Elementary School, but she didn’t make it to the park or school Friday Oct. 5, 2012. An Amber Alert has been issued. (AP Photo/Westminster Colorado Police Department)

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • 150105_10151341575584305_1291829664_n

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Department released new photos of missing 10-year-old Jessica Ridgeway. The picture is dated June 25th, 2011.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is dated July 6, 2006.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo of Jessica is dated July 13, 2006.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Arvada Police spokeswoman Jill McGranahan, left, and Westminster Police spokesman Trevor Materasso, right, address the media regarding a body found lat Wednesday in Parttridge Park in Arvada during a press conference at the Westminister Police Department Thursday, Oct. 11, 2012 in Westminister, Colo. The search missing 10-year-old Jessica Ridgeway will continue, police said Thursday. (AP Photo/Barry Gutierrez)

  • Missing School Girl

    A police officer walks through a field of tall grass searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    Denis McLaughlin leads his search and rescue dog through a field of tall grass searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    Members of a search and rescue team use a dog while searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    A member of a search and rescue team leads his dog through a field of tall grass searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    A Westminster police officer sits in her partrol car at the home of ten-year-old Jessica Ridgeway in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    A missing poster for ten-year-old Jessica Ridgeway is seen in Broomfield, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Arvada Police spokeswoman Jill McGranahan, left, and Westminster Police spokesman Trevor Materasso, right, address the media regarding a body found lat Wednesday in Parttridge Park in Arvada during a press conference at the Westminister Police Department Thursday, Oct. 11, 2012 in Westminister, Colo. The search missing 10-year-old Jessica Ridgeway will continue, police said Thursday. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near the 9800 block of Alkire St. on the west side of Stanley Lake in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether a body found in Pattridge Park on Wednesday is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)