Personnel from across South Dakota and elsewhere will search for Serenity Dennard this weekend.
Serenity is a nine-year old girl who left the Black Hills Children's Home near Rockerville on February 3rd.
Authorities say she was not dressed for the frigid conditions when she walked away from the facility.
Pennington County Sheriff Kevin Thom says officials will use dog teams as part of the search efforts in an area near the Children's Home.
"They're cadaver dogs. Because, we believe that she is in the woods...she is deceased at this point. So, we'll use cadaver dogs, and again they come from out of state and around South Dakota. A total of ten teams."
Thom says a fixed-wing aircraft and a helicopter will assist the personnel and dog teams in their search. The Sheriff says there's a separate investigative track where federal assistance has been used.
"We've interviewed over 260 people, we've served some search warrants for some records - particularly, phone records. We've followed up a number of in-state and out-of-state leads - we've worked with other law enforcement agencies to assist with those - we've asked the FBI to assist with those."
Thom says the FBI has reviewed the case file and provided technical assistance.
He says his agency has also received support from the South Dakota Division of Criminal Investigation, South Dakota Wildland Fire, and numerous agencies throughout the Rapid City area.
Thom says people are asked to contact authorities if they see anything or have any information about this case.