Near Comfrey in Cottonwood County, Minnesota — The American Midwest (Upper Plains)
Glaciers Marked the Rock
Photographed By Ruth VanSteenwyk, October 1, 2019
1. Glaciers Marked the Rock Marker
This outcropping is an “erosional high”-rock smoothed off by glaciers.
Continental glaciers advanced and retreated across this region many times in the last million years, before leaving for good about 12,000 years ago. This extremely hard quartzite rock provides a unique record of glacial history. Individual glaciers, each carrying a bottom layer of rocks and moving in a separate direction, made the crisscrossed lines that you see here. Other rock retains evidence of only the most recent glacier.
Ancient Rivers
The many fipple marks seen here were formed by currents in an ancient river. Shallow river currents, like those pictured above, were rapidly covered by mud and then subjected to heat and pressure for millions of years. The deposited sands of the river gradually solidified into sandstone and then into the quartzite you see today.
Erected by Minnesota Historical Society.
Topics. This historical marker is listed in these topic lists: Environment • Parks & Recreational Areas.
Location. 44° 5.502′ N, 95° 3.032′ W. Marker is near Comfrey, Minnesota, in Cottonwood County. Marker is on 510th Avenue (County Road 2). Marker
this page online
Other nearby markers. At least 8 other markers are within 11 miles of this marker, measured as the crow flies. Florence Cook Roefer Prairie Trail (a few steps from this marker); Survival Through Fire (approx. 0.2 miles away); Prairie Preservation (approx. ¼ mile away); Why did people come to this region? (approx. ¼ mile away); How did this Prairie get here? (approx. 0.3 miles away); Sanborn, Minnesota Veterans Memorial (approx. 8.1 miles away); Veterans Memorial (approx. 10.7 miles away); a different marker also named Veterans Memorial (approx. 10.8 miles away). Touch for a list and map of all markers in Comfrey.
More about this marker. Jeffers Petroglyphs is home to about 5,000 sacred rock carvings, also called petroglyphs, made by the ancestors of today’s Native Americans. Jeffers tells the story of this continent like no other place — connecting visitors to those who lived and traveled in ancient times across what is now known as North America.
Also see . . . More at the Jeffers Petroglyphs website. (Submitted on October 10, 2019, by Ruth VanSteenwyk of Aberdeen, South Dakota.)
Photographed By Ruth VanSteenwyk, October 1, 2019
2. Glaciers Marked the Rock Marker
Photographed By Ruth VanSteenwyk, October 1, 2019
3. Jeffers Petroglyphs
Photographed By Ruth VanSteenwyk
4. Jeffers Petroglyphs Historic Site Sign
Credits. This page was last revised on October 10, 2019. It was originally submitted on October 10, 2019, by Ruth VanSteenwyk of Aberdeen, South Dakota. This page has been viewed 131 times since then and 11 times this year. Last updated on October 10, 2019, by Ruth VanSteenwyk of Aberdeen, South Dakota. Photos: 1, 2, 3, 4. submitted on October 10, 2019, by Ruth VanSteenwyk of Aberdeen, South Dakota. • Mark Hilton was the editor who published this page.
