What a great day of cycling! I rode 51 miles today, and our route was through the rolling Loess Hills of western Iowa:
The Loess Hills are generally located between 1 and 15 miles (24 km) east of the Missouri River channel. These hills are the first rise in land beyond the flood plain, forming something of a "front range" for Iowa, and parts of Missouri and Nebraska adjacent to the Missouri River.
During the last Ice Age, glaciers advanced into the middle of North America, grinding underlying rock into dust-like "glacial flour." As temperatures warmed, the glaciers retreated and vast amounts of meltwater and sediment flooded the Missouri River Valley. The sediment was deposited on the flood plain, creating huge mud flats. When meltwaters receded, these mud flats were exposed. As they dried, the fine-grained silt was picked up by strong prevailing westerly winds. Huge dust clouds were moved and redeposited over broad areas. The heavier, coarser silt was deposited close to the Missouri River flood plain, forming vast dune fields. The dune fields were eventually stabilized by grass. Due to the erosive nature of loess soil and its ability to stand in vertical columns when dry, the stabilized dunes were eroded into the corrugated, sharply-dissected bluffs we see today.
Not only are they geologically interesting; they also make for great cycling along the Loess Hills Scenic Byway. The wind vascillated between head wind and tail wind, and it was sunny all day.
We also couldn't resist the photo op in front of this wonderful old sign on the side of a building in Pacific Junction, Iowa:
And we ended the day with a visit to the Missouri River Basin Lewis & Clark Visitor Center in Nebraska City, Nebraska. Informative and fun exhibits, including a replica of the L&C keelboat that induced some roleplaying:
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