Lost in the Everglades — Carolyn Keene

DEVELOPERS ARE CLASHING WITH NATURE LOVERS -- AND NANCY'S BEST HOPE IS AN ANCIENT STATUE!
Visiting an old friend in Florida, Nancy, Bess, and George are awed by the beauty of the Everglades. But Jade Romero, a young park volunteer, is missing. She went backcountry camping and never returned. When Nancy agrees to search for her, she also learns about a priceless Native American statue of a panther hidden in the wilderness.
A clue leads Nancy to Panterra Corporation, which is developing a big mall at the edge of the Everglades. Then a close escape on the road and a threatening note convince Nancy to search the backwoods. Deep in untamed country, alligators are menacing the girls -- but the worst danger is coming from enemies they never suspected!