Deep Time: Four Secret Geology Treks
Grand CanyonGrand Canyon National Park Service
Among the most spectacular, but least appreciated, views in the Western United States are those into what's called “deep time.” That's the Earth's history that stretches back tens of thousands, millions and even hundreds of millions of years before humans existed. There are a lot of famous spots for such views, like the Grand Canyon. But there are lots more intimate windows into that past. Here are a few of them:
Ichthyosaur State Park
Berlin-Ichthyosaur State Park in central Nevada's Shoshone Mountains provides two very different views into the past. One is Berlin, a ghost town that's now on the National Register of Historic Places. Two miles away is the deep-time view, at the ichthyosaur site.
Ichthyosaurs were whale-sized reptiles that ruled Earth's oceans more than 217 million years ago. You can see the bones of several of these giant ichthyosaurs at the site. The local lore is that early miners were the first to find ichthyosaur bones and used them for building hearths. It wasn't until 1928 that Siemon W. Muller of Stanford University realized they were ichthyosaur bones. But it wasn't until 1954 that excavations started.
Today you can enjoy the fruits of all that labor, as long as you are willing to venture to this remote part of Nevada. More information can be found here.
Death Valley National Park
Tucked away in the canyons of Death Valley National Park are scores of remarkable windows into the past. One of them is Copper Canyon, known for its footprints and fossils of camels, horses and mammoths that lived along the shores of a lake about 4 million years ago.
This is a rare place to explore and is closed except for ranger guided tours a few times every year. Check with the rangers at the Furnace Creek Visitor Center before you visit to find out when the next tour is scheduled.
But don't be discouraged if you can't make the Copper Canyon hike. There are loads of other amazing deep time windows in Death Valley, stretching back to more than a half a billion years ago. The past is everywhere in Death Valley.
Near the middle of the continent there is a fossil so huge that it's only fully visible from space. The Sandhills of Nebraska is the largest sand dune field in North America and they are locked into place by vegetation.
These dunes formed when the climate there was much drier than today and they are preserved because early settlers found the sandy ground unplowable. Geologists have excavated the dunes and found bison footprints from ice ages, as well as 3 million-year-old mammoth bones.
The Sandhills are also famous for their birds, especially the Sandhill cranes. A great way to see the Sandhills is to follow the State of Nebraska's SandHills Scenic Byway. More information about the Sandhills can be found here.
Karen Holzer, USGS
This is perhaps the only geology trek on the list that takes you into the future as well as the past. Glacier's majestic peaks were carved by great glaciers more than 12,000 years ago.
Today's remaining glaciers date back to about 7,000 years ago and numbered about 150 when the park was established in 1910. By 2010 there were only 25 glaciers left larger than 25 acres. The U.S. Geological Survey estimates that all of the glaciers could be gone by the year 2030.