“Maine’s Ice Age Trail: Down East Map and Guide” shows schists, eskers and other ice-age remnants.

Of course bedrock geology is a whole different thing — ever shifting, folding, erupting from the deep — as I learned further along in my quest for geologic knowledge from any source I could find (books, maps, geology talks and guided field trips). In most areas, Maine’s bedrock geology (volcanic and tectonic in origin) is buried under its surficial geology (glacial deposits), except for exposed outcrops, many of them scratched and polished by the shifting glacier as it advanced and retreated.

Often what we seek out and discover on our own seems more compelling than information pressed upon us in school, especially when such discoveries involve maps, exploring and finding geologic treasure — some buried, but most right in plain sight if we know where to look. Now, thanks to Harold Borns, UMO professor emeritus of glacial geology and climatology, map designer and senior cartographer Michael Hermann, and the University of Maine Press (with local, state, and federal support), we know exactly where to look for 46 of eastern Maine’s most interesting and accessible features left by the last ice age.

“Maine’s Ice Age Trail: Down East Map and Guide”(University of Maine Press, 2007, $8.95) — the first in a planned series of four Maine Ice Age Trail regional maps — shows Maine’s eastern coastal zone stretching from eastern Hancock County across Washington County, where many of the best examples of glacial landforms in the state can be easily seen thanks to the expansive blueberry barrens. These and many other areas on the map are relatively undeveloped, making features like eskers and moraines (color-coded on the map) more visible and accessible than if obscured by sprawling development.

The route of the Ice Age Trail follows the retreating margin of the Laurentide Ice Sheet. Each of the 46 numbered sites is located on the map with a purple silhouette of a wooly mammoth (one of the beasts that roamed the tundra on retreat of the ice sheets). Keyed to each icon, on the back of the map, are precise directions and a description of geologic highlights of the site. In the margins are diagrams, photos, and text interpreting the different types of glacial features and how they were formed.

By putting this information together with a self-guided tour of any combination of numbered sites (or, for the more adventurous, a do-it-yourself tour following the color-coding along with the Maine Atlas), there’s enough here to inspire countless glacial adventures around coastal Hancock and Washington counties.

A few of the more notable (and road-accessible) sites within reach of Ellsworth include: the Agassiz Historical Outcrop of glacially polished and grooved schist (Stop 6), noted by pioneering glacial geologist Louis Agassiz, on Route 1A next to Woodland Studios; the McFarland Hill Delta (Stop 7, straddling two huge gravel pits a mile east of Ellsworth on Route 1; an esker, ancient shoreline, and glacial grooving along Route 184 in Lamoine (Stops 8 and 9); a cluster of sites around the Pineo Ridge Delta (Stops 17 through 22), north of Harrington; and, saving the best for last (if making a grand loop), the Whalesback, a two-mile portion of the 120-mile Katahdin Esker used as a roadbed along this section of Route 9 in Aurora (Stop 46), offering dramatic views out over the Middle Branch of the Union River to Lead Mountain.

Eskers — caterpillar-shaped ridges of gravel dumped by meltwater tunnels — are my favorite glacial features, especially when found in their natural state in wooded areas or along streams and lakeshores. There are also plenty of nearby end moraines, annual deposits of sand and gravel dropped along the margin of the retreating glacier. These are experienced as a series of “thank-you-ma’ams” as one drives over them on local roads in places like Oak Point and Newbury Neck — also en route from South Penobscot to Sedgwick, but that’ll be on the next map in the series showing the Penobscot Bay region, to the west. I can hardly wait.

Maine’s Ice Age Trail project was initiated when Pamela Person of Orland (an executive committee member of the Maine Global Climate Change Institute) discovered that Wisconsin, another state with distinctive glacial features, has made them the focus of a popular geotourism trail. She brought this to the attention of Professor Borns, thinking that coastal Maine’s glacial landscape, unique in the eastern United States, would be well suited for a similar education-cum-ecotourism trail. The University of Maine’s Climate Change Institute partnered with the Maine Geological Survey, Maine Department of Conservation, and other state and federal agencies — in collaboration with an advisory team representing scientific concerns, tourism interests, and climate change issues — to develop the map, six years in the making. A grant from the National Science Foundation funded the original edition of the award-winning map, and the second printing is now available through the University of Maine Bookstore.

Pick up a copy and check out the glacial landscape!

Jane Crosen is a mapmaker, writer and freelance editor who lives in Penobscot. Her hand-drawn maps are displayed on her Web site, mainemapmaker.com. For more information about “Maine’s Ice Age Trail,” visit http://iceagetrail.umaine.edu To purchase the map, visit the University Bookstore’s Web site, bookstore.umaine.edu or call (888) 863-4438. Other resources include the Maine Geological Survey’s Web site, maine.gov/doc/nrimc/mgs, which also sells an array of geological maps of Maine, bedrock and surficial. D.W. Caldwell’s book, “Roadside Geology of Maine” is a good guide to Maine geology.