ATLANTA — Treasure-hunt fans will soon have a new quest that takes them from Georgia’s mountains to its marshes.To celebrate its 85th anniversary this year, Georgia’s state park system is kicking off a new game called Birthday Bash Geocache. Using a hand-held GPS, players find hidden caches while exploring some of Georgia’s most scenic locations. Park officials teamed up with Georgia Geo-Campers volunteers to create the quest, which includes trackable “geocoin” prizes.