Colorado Parks & Wildlife Research Library

14-year-old Will Burrows has little in common with his strange, dysfunctional family. In fact, the only bond he shares with his eccentric father is a passion for archaeological excavation. So when his dad mysteriously vanishes, Will is compelled to dig up the truth behind his disappearance. He unearths the unbelievable: a subterranean society that time forgot. "The Colony" has existed unchanged for a century, but it's no benign time capsule of a bygone...

Illustrations and rhyming text reveal events happening in varied environments, from an icy sea to a blistering desert, while very different things occur down below.

"In the underground city of Caverna, the world's most skilled craftspeople toil in the darkness to create delicacies beyond compare-- wines that remove memories, cheeses that make you hallucinate, and perfumes that convince you to trust the wearer, even as he slits your throat. On the surface, the people of Caverna seem ordinary, except for one thing: their faces are as blank as untouched snow. Expressions must be learned, and only the famous Facesmiths...

In the year 241, twelve-year-old Lina trades jobs on Assignment Day to be a Messenger to run to new places in her decaying but beloved city, perhaps even to glimpse Unknown Regions.

Have you ever seen a manhole cover with little glass circles in it and wondered why it was different from the others? Did you ever imagine that there were actually tunnels under the sidewalks? You'll be surprised to find out how many cities in Colorado had these tunnels. And they're still under our streets! Those manhole covers imbedded with glass circles, many that have turned purple with age, allowed light into the tunnels below. The Tunnels Under...

As fourteen-year-old archaeologist Will and his friends plummet down a subterranean pore, they face deadly creatures and discover a strange fungal shelf, which not only reveals artifacts from ancient civilizations, but clues to a lost land at the end of the Earth.

Teenager Eliza and her friends are going to explore a cave near their upstate New York home, but first her friends insist on dragging her to Drowner's Swamp, a bog legendary for its dangerous sinkholes, and a place which her mother has frequently warned her about; Eliza does not want to go, and when the earth opens up and swallows her she finds herself in a system of caves--and what she finds living there is strange and dangerous beyond anything the...

Armed with secret knowledge, Juliette, now mayor of Silo 18 and her crew set out to rescue a world she hates but now understands better -- the world of the Silos with its rigid rules and terrible consequences for disobedience.

Seventeen-year-old Larkin leads a band of magical outlaws through a subterranean realm of horrors and certain death.

What waits Beneath? Pat O'Toole has always idolized his older brother, Coop. He's even helped Coop with some of his crazier plans -- such as risking his life to help his big brother dig a tunnel underneath their neighborhood in the suburbs of Washington, DC. Coop is . . . different. He doesn't talk on the phone, doesn't use email, and doesn't have friends. He's never really cared for anything but the thrill of being underground and Pat. So it's no...