Pikes Peak Overlook Landscape Interpretation

Pikes Peak Overlook Landscape Interpretation. . Across this impressive gorge of the Mississippi River is the mouth of the Wisconsin River. The steeply notched valleys of both rivers are carved into sedimentary bedrock which underlies the level, plateau-like uplands and forms the abrupt, picturesque bluffs along the valley margins. The layered rocks originated as loose sediment on sea floors 450 to 550 million years ago, and over time hardened into strata dominated by dolomite and sandstone. Fossil remains of marine life are seen in rocks throughout the area. , These valleys began to develop over 1 million years ago. The melting of vast ice sheets released enormous volumes of water, sand, and gravel which scoured, filled in, and shaped the valley profiles periodically until about 9,500 years ago. The towns of Bridgeport and Prairie du Chein, Wisconsin, are built on terraces within the valleys that mark two different levels of sediment accumulation during these glacial meltwater floods. , In 1673, a small band of French explorers led by Father Jacques Marquette and mapmaker Louis Jolliet journeyed in two bark canoes down the Wisconsin River to this site, becoming the first Europeans to see Iowa. Lt. Zebulon Pike, for whom this overlook and the Colorado peak were named, evaluated this location for a fort in 1805. The islands and pools seen in the Mississippi valley today are a result of ponding from the lock and dam system built in the 1930s. This valley provides valuable habitat for many species of fish and wildlife, and a dependable avenue of commerce for the region. , Gift of Bruce and Susan Renaud.