State Rock: Iowa Geode (1967)
Iowa is primarily known for its “Keokuk geodes.” Once being under a Cretaceous shallow sea Iowa now has sedimentary deposits. Accordingly, Iowa also has fossils as well as several caves. In addition, numerous meteorites have been recovered in Iowa (for meteorite hunters, a meteorite fall on the Iowa terrain is much, much more desirable than trying to find meteorites in the Rocky Mountains or heavily forested areas).
Please note that rock collecting locations are always changing so be sure to check with the site owner for the most current information before going.
Dig safe, never go underground, and make sure to get permission from the landowner to search for and collect rocks.