MIDDLEBURY, Vt. (AP) – Lake Champlain’s bottom has been brought to life through a complex mapping project that reveals previously unknown shoals and shipwrecks.

The comprehensive and detailed map makes all others seem quaint and outdated – and with good reason: Existing nautical charts were based on fewer than 10,000 depth measurements taken by the federal government in 1879. The new color-coded map used roughly 735,000 measurements gathered over eight years and processed for another two.

“Not only is Lake Champlain among our nation’s most precious resources, but historically it may be the most significant water body in North America,” said Sen. Patrick Leahy, D-Vt., at the map’s unveiling Thursday. “The survey results clearly document the lake’s extraordinary collection of shipwrecks.

“This new map, with its new insights into the bottom topography of the lake, will also prove to be an invaluable aid to researchers in understanding the role of hydrodynamics in the lake’s living ecology,” said Leahy.

The mapping project was undertaken by Middlebury College and the Lake Champlain Maritime Museum and financed in part by federal appropriations secured by Leahy.

It was initiated in 1996 as a response to the invasion of zebra mussels and the fear they would ruin historic shipwrecks on the lake’s bottom.

Researchers say that when the project began less than 10 percent of the lake’s bottom had been examined. The project used state of the art marine survey technology, primarily a side-scan sonar that worked with Global Positioning Systems and computers to plot the boat’s position and depth information.

The project revealed more than 70 previously unknown shipwrecks.

“To redefine through this new map the underwater topography of Lake Champlain has been remarkable,” said Art Cohn of the Lake Champlain Maritime Museum.

Middlebury College faculty members Pat and Tom Manley used Middlebury oceanography and marine geology students and the Middlebury research vessel, the R/V Neptune, to gather the lake depth information over eight years. The Manleys worked with other students for another two years to process the information.

“Middlebury College faculty members Pat and Tom Manley and their student researchers have made an enormous contribution to our understanding of Lake Champlain with the creation of this map,” said Middlebury President Ronald D. Liebowitz.

The “Whole Lake Survey” was financed primarily through the Lake Champlain Basin Program, the Freeman Foundation and the Lintilhac Foundation.