The Colorado Curveball (Ballpark Mysteries, Bk. 16)

Mike and Kate arrive in Colorado to a ballpark covered in snow! Luckily, the stadium has a heater that can melt the fluffy flakes in time for next day's game. But when the ballpark engineers get a mysterious note saying that someone may tamper with the scoreboard, the snow becomes the least of the cousins' problems. It's time for Mike and Kate to switch into sleuth mode and solve a mystery that will take them underground, a mile above sea level, and even face to face with a dinosaur!