The Mark of Athena
Rick Riordan
Heroes of Olympus (3)
Nexus
Yuval Noah Harari
The Jupiter Catastrophe
Brandon Q. Morris
Ice Moon (5)
Command and Control
Eric Schlosser
Hiking Colorado: A Guide to the State's Greatest Hiking Adventures
Sandy Heise & Maryann Gaug
Hiking through History Colorado
Robert Hurst
Hiking Waterfalls in Colorado
Susan Joy Paul
60 Hikes Within 60 Miles: Denver and Boulder
Kim Lipker
Mountaineering
The Mountaineers