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About 13,000 years ago, the shoreline of Lake Uri sat in a very different place.
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The water stood much higher than it does today.
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Roughly 200 feet higher, that's about 61 meters.
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The land that now forms the southern shore of Lake Uri was once the edge of a much larger
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glacial lake called Lake Warren.
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This happened near the end of the last ice age.
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Huge continental glaciers, it covered much of North America.
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In places that the ice reached more than one mile thick, about 5,280 feet or 1.6 kilometers,
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Temperatures they slowly warmed, the glaciers began retreating northward.
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And when that ice melted, it released enormous amounts of water.
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The melt water pulled along the southern edge of the glacier and formed a series of temporary
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One of the earliest and largest of these was Lake Warren.
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At its height, Lake Warren stretched across parts of present-day Michigan, Ohio, Pennsylvania,
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The lake extended hundreds of miles along the ice front and covered thousands of square
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miles of land that is now dry ground.
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For long periods, the water remained high and stable.
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Waves worked against the shoreline year after year.
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They pushed sand inland and cut into the softer earth along the coast.
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Blue's waves built wide sandy beaches and carved steep bluffs that still line parts
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of Lake Eerie today.
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In several places those bluffs, they rise close to 100 feet, about 30.5 meters.
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These cliffs marked the ancient edge of Lake Warren.
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Geologists can still trace the shoreline today.
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Old beach ridges created by Lake Warren, they run inland across northern Ohio and western
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These ridges are very long narrow bans of sand and gravel left behind by wave action.
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And in some places those former beaches, they sit several miles inland from modern shorelines.
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Roads, farms, and entire towns now rest on what used to be the edge of that ancient lake.
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As the glaciers continued retreating, new drainage outlets, they opened towards the east.
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Water from Lake Warren slowly escaped through these lower channels.
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For thousands of years, the lake level dropped several stages before settling into what
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we know now as Lake Eerie.
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But the landscape still carries the marks of that earlier lake.
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The sandy beaches along Lake Eerie today, they were first shaped by Lake Warren.
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The high bluffs above the water, they were cut by its waves.
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Creeks, like 18 mile creek, they still follow valley's form during those glacial years
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before flowing into Lake Eerie.
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And along the Lake Eerie shoreline today, and you're looking across a basin at once
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held a much larger lake.
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And the ground beneath your feet, well it was part of a beach that formed more than
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These are interesting things with J.C.