A team of private-sector outdoorsmen and another of Yellowstone National Park personnel and volunteers are preparing missions ...

Henke, the father of a Minnesota native who went missing in Yellowstone last fall, announced on July 6 that the search for his son, Austin King, will resume later this month.

Jaime King is engaged to investor Austin Sosa, and "is very close with his family," a source exclusively tells PEOPLE.

"All I want to be able to do is say as a dad, I did everything I could to give the best chance of finding him," wrote Brian King-Henke, vowing to bring Austin home.

Over 100 people have covered more than 3,225 miles by air and ground to search for King since he went missing. King, who is originally from Winona, worked in Yellowstone as a concession employee.