Loess Hills Landform

Bordering most of the western edge of Iowa, the Loess Hills, pronounced "luss", are a natural and geological wonder.  These steeply sloping bluffs are noted for their composition of silty, buff-colored, windblown soil and their depth of over 200 feet.  Only in China are there loess deposits of greater depth.

Produced over thousands of years by the grinding of glaciers, huge quantities of this loess was exposed across a vast river valley, now called the Missouri, where it was picked up and carried by prevailing westerly winds.  Slowly layers of this loose, soft soil formed the hills.  Most of the deposits occurred between 18,000 and 150,000 years ago.

Since then running water and erosion have formed the sharp angles and deep ravines seen today.  With little vegetation to hold it, the soil dissolved like sugar.  Spurs, ridges, valleys and ravines formed to give the Loess Hills its distinct character.  Once Bohumil Shimek stated that "the Hills appear like the giant swell of a stormy sea which has been suddenly fixed."

Dry prairies emerged as the dominate habitat with unique and rare plant and animal species found nowhere else in Iowa.  In areas too steep to plow or graze, they represent most of Iowa's surviving native prairie.  After pioneer settlement and suppression of wildfires, woodlands took over dramatically changing the landscape to what we see today.

Loess Hills National Scenic Byway

The Loess Hills National Scenic Byway, Iowa's first Scenic Byway, forms a spine with several excursion loops throughout the Loess Hills formation.  This Byway was designated one of the Nation's top ten Scenic Byways and gives a taste of the Loess Hills' many components, from small towns to metropolitan areas, wilderness, vistas, culture, history, and geology.

The scenic byway main route consists of 220 miles of paved highway or county road in a general north to south direction paralleling Interstate 29.  When traveling on the scenic byway, the traveler has the option of selecting 13 excursion routes for additional experiences, many on gravel roads.

For further information, contact the Missouri Valley Chamber of Commerce at 712-642-2553 or the Harrison County Welcome Center at 712-642-2114.  Tours are also offered by the Loess Hills Hospitality Association at 712-886-5441.