Grand Gulf State Park

Grand Gulf State Park near Thayer, Missouri, consists of 322 acres (130 hectares) encompassing a forked canyon that is the remnant of an ancient collapsed cave system. The Grand Gulf is nearly a mile long and up to 130 feet (40 m) deep with shear sides. An uncollapsed part of the original cavern roof spans 200 feet (61 m), creating the largest natural bridge in Missouri.

A watershed of 26 square miles (67 km²) feeds into the gulf which itself drains into a cave entrance at its eastern end. Dye traces have shown that water entering the cave in Grand Gulf emerges 1 to 4 days later at Mammoth Spring in Arkansas, 9 miles (14 km) distant.

The land that is now the park was acquired by conservationist Leo Drey before becoming part of the Missouri state parks system. The park has picnic tables and toilet facilities and is operated by the state as a day use area with no camping. Because of heavy foliage the Grand Gulf is best viewed in winter months.

References

* Citation
last =Beveridge
first =Thomas R.
title =Geologic Wonders and Curiosities of Missouri
publisher =Missouri Division of Geology and Land Survey
year =1980
pages=335-344
location =Rolla
id = Library of Congress Card Catalog No. 78-69968
* cite web
title =Grand Gulf State Park - Missouri State Parks and Historic Sites, MoDNR
publisher = Missouri Department of Natural Resources
date =2006-09-11
url =http://mostateparks.com/grandgulf.htm
accessdate =2007-08-03