BEMIDJI, Minn. — Eleven thousand years ago, warming temperatures signaled the end of the Pleistocene-epoch glaciation of North America and had the Laurentide Ice Sheet in full retreat. At its grandest stage, the glacier was two miles thick and reached as far south as Dickinson County, Kan. It radically altered the land unveiled by its departure, carving out tens of thousands of lakes in its wake as it crept north into Canada.

The most common of these lakes, tabbed “fossil icebergs” by author Robert Finch, are kettle lakes. The kettles were created when blocks of ice left behind by the retreating glacier melted, leaving depressions in the landsdcape that were later re-filled by melting snow and rain water.

Bemidji State University alumnus Dr. Robert Thorson counts himself among those who have become entranced by the kettle lakes. His fascination with the lakes has led the University of Connecticut geology professor and environmental columnist for the Hartford Courant to pen “Beyond Walden: The Hidden History of America’s Kettle Lakes and Ponds.”

The book, titled in reference to America’s most famed kettle lake, Walden Pond in Concord, Mass., is Thorson’s second in a planned trilogy on signature landforms. It examines the geology, paleontology, archaeology, limnology and history of the kettle lakes between Maine and Montana.

Thorson is returning to his alma mater on Thursday, July 9, to deliver a lecture on the book and on the geography and history of kettle lakes. The lecture, which will be free and open to the public, will be held in room 245 of Bemidji State’s Sattgast Hall.

The lecture will be one of many stops on Thorson’s journey across the northern United States with his wife to visit the culture and community surrounding kettle lakes. From June 29-July 15, the Thorsons will travel by car from Maine to Montana and provide a daily written and pictorial account of “quirky places… local folks and lake professionals and a chronicle of unexpected events” on a blog Thorson has established to chronicle the journey.

“Beyond Walden” is the sixth book authored by Thorson. His first book on signature landforms, “Stone by Stone: The Magnificent History in New England’s Stone Walls” won the 2003 Connecticut Book Award for nonfiction. In 2005, he published “Exploring Stone Walls: A Field Guide to New England’s Stone Walls.”

Thorson has been with the University of Connecticut since 1987, when he started as an associate professor of geology and geophysics. He was promoted to professor in 1996, and since 2004 has served as a professor of geology in the university’s Department of Ecology & Evolutionary Biology and Department of Anthropology. Additionally, since 2005 he has been an honors fellow in the University of Connecticut’s Honors Program and coordinator of the university’s Stone Wall Initiative. He also has served as a visiting scholar at the Universidad Tecnica Federico Santa Maria in Valparaiso, Chile (1999-2000), where he was a Fulbright Scholar, at Dartmouth College (1991-92) and at Yale University (1990).

Prior to joining the faculty at Connecticut, Thorson was on the faculty at the University of Alaska, Fairbanks as an assistant professor; was the head of surficial geology in the Earth Sciences Division at the University of Alaska Museum, founding director of the Alaska Quaternary Center, and an assistant professor at the University of Wisconsin-Oshkosh. He also worked for the U.S. Geological Survey from 1975-80.

Thorson has served on the advisory board for the Connecticut Center for the Book, a Library of Congress program devoted to public literacy, since 2005.

Thorson graduated from Bemidji State College in 1973 with a bachelor’s degree in earth science teaching. He holds a master’s degree in geology from the University of Alaska, Fairbanks and a doctorate in geology from the University of Washington.

On the Web:
• Robert Thorson at the University of Connecticut: http://thor.uconn.edu/
• Thorson’s “Walden to Wobegon” road trip blog: http://waldentowobegon.blogspot.com/

For Your Calendar:
Thursday, July 9 – 4 p.m. — University of Connecticut geology professor and Bemidji State College alumnus Dr. Robert Thorson will lecture on his book, “Beyond Walden: The Hidden History of America’s Kettle Lakes and Ponds,” on the geography and history of glacier-formed kettle lakes in the United States. Location: Sattgast Hall 245; Bemidji State campus. Admission: Free and open to the public. Information: Bemidji State University College of Arts and Sciences; (218) 755-2988.