When Ken and his twin sister Chris visit their friend Marty in Utah, they can't wait to go hunting for fossil remains of a dinosaur. With the help of a old map, can they locate the mysterious dinosaur graveyard? An exciting adventure-mystery!

"A mysterious old map, a strange night prowler, and a night spent in a cave help to make this an exciting mystery for the 8 to 12 year old." -- Hartford Courant

"In addition to a good story line, the book contains much basic information and scientific background." -- The Pittsburgh Press