Miles: 3954The Land of Pop and Sacks
But first we had to leave Iowa. We packed up our campsite and went for a short hike around Ledges State Park. We particularly wanted to check out the ledges, oddly enough. These are sandstone walls created by the Pea’s Creek and are now a home for birds. The road there was washed out, at least according to the signs. When we got down there, we discovered that only a low rider Escort would have a problem with the few inches of water, but whatever. The signs and maps of this park were an Eagle Scout project waiting to happen. The trail map we had made no sense and we felt no sense of security when going hiking. In fact, several times we worried that we were going to wind up lost in the wilds of Iowa.
After our hike we booked it to the Loess Hills region of Iowa, which is right along the Iowa/Nebraska border. The creation of the Hills went something like this: Although early geologists assumed loess was either fluvial (deposited by a river) or lacustrine (formed in a lake), today we know that loess was eolian (deposited by the wind). During the Ice Age, glaciers advanced down into the mid-continent of North America, grinding underlying rock into a fine powderlike sediment called "glacial flour." As temperatures warmed, the glaciers melted and enormous amounts of water and sediment rushed down the Missouri River valley. The sediment was eventually deposited on flood plains downstream, creating huge mud flats.
During the winters the meltwaters would recede, leaving the mud flats exposed. As they dried, fine-grained mud material called silt was picked up and carried by strong winds. These large dust clouds were moved eastward by prevailing westerly winds and were redeposited over broad areas. Heavier, coarser silt, deposited closest to its Missouri River flood plain source, formed sharp, high bluffs on the western margin of the Loess Hills. Finer, lighter silt, deposited farther east, created gently sloping hills on the eastern margin. This process repeated for thousands of years, building layer upon layer until the loess reached thicknesses of 60 feet or more and became the dominant feature of the terrain. (Consider this your footnote: www.usgs.gov)
There are some neat forested areas, as well as some steeply planted corn. It’s a very pretty area, and our pictures don’t really do it justice, as they don’t capture the vastness of the landscape or the abruptness of the hills.
We popped out of the Loess Hills in Sioux City, IA and continued our way to Sioux Falls. The South Dakota Visitor’s Center has a very clever way of providing its patrons with history lessons: they rent sets of 4 CD’s that provide narration of points of interest along the two major highways in the state. We rented a set and continued North. We listened to some of the history as we drove North on Interstate 29, and though we never stopped at any of them, we did decide that tomorrow we would go to Garreson, SD, where Jesse James allegedly made a daring escape after a bank robbery.
Once in Sioux Falls, we decided to rent a hotel room for the night to take advantage of some air conditioning and some free WiFi internet. So we could update our blog. Like this. See?
Correction Samuel Clemens did indeed get his pen name from the steamship term for "safe waters," but the term "Mark" does not mean ten. We swore it was written down like that somewhere in the museum, but the correct etymology was also written down: Mark apparently refers simply to the depth mark. Twain does indeed mean two. And twelve feet is indeed safe passage for a steamboat. However, the reference was to two fathoms, where one fathom is six feet. And now you know.