When not climbing in the Alps, searching for rare plants in the desert, or mountain biking through some jungle, I am the curator of the Jay I. Kislak Collection of the Archaeology of the Early Americas at the Library of Congress, and a lecturer at the Rare Book School, at the University of Virginia, teaching the linguistics and ethnobotany of the Mesoamerican Codex.

An avid mountaineer, I am a frequent contributor to Alpinist Magazine, where I write about high-altitude physiology, glaciology and the history of mountaineering.

Formerly of the Smithsonian's Museum of Natural History, my research has focused on the linguistics & ethnobotany of the Cahuilla, in the deserts of southwestern California & Joshua Tree National Park and on the botanical cognates in the Uto-Aztecan language family.

For the last few years I have been making my way through the huge body of notes and ethnobotanical material on the Cahuilla left by John Peabody Harrington, along with notes on the little known Kitanemuk Serrano, especially his "notes on plants" from 1917.

Interested in the earliest plant collecting from the Americas, I have also participated in archaeobotanical studies of flora, including a recent investigation of ancient agave and mycotrophic plants. My work on the linguistics of Maya and Nahuatl ethnobotany is a featured project at Harvard's Dumbarton Oaks Plant Humanities Initiative.

The author of more than one hundred articles and books on exploration and cartography, including the New York Times bestseller, MAP: Exploring the World, my work has been featured in many media outlets including the New York Times, Washington Post, the BBC, CBS News and NPR’s All Things Considered.

My most recent book, Collecting for a New World, examines the history of the archaeological collections at the Library of Congress, where I also write the Excavating Archaeology Series for the blog, Worlds Revealed.

I often find myself pondering the intricacies of botanical classification, wondering about the mysteries of contained in ancient DNA, and marveling at the biological complexity to be found in Darwin’s tangled bank.