Underneath the surface

For John Laird, naturalist at Hamilton County Conservation, caving has been part of his life for years now.

Laird previously worked at Forestville Mystery Cave state park in Minnesota. His experience with exploring caves began well before that.

“My family has always had an interest in caves. When we went on vacations growing up, we would stop at caves when we went to national parks and travel the country,”

Now, Laird is planning to share his experience with interested persons during a program this Saturday called, “Jewels of the Underground.” Laird will present about the caves across the the country, where they are found in Iowa, how those caves were formed, what equipment that people use to explore caves and more. The program will begin at 2 p.m. at the Hamilton County Conservation office at Briggs Woods Park. It is open to all ages.

In Iowa, most caves are found in the northeastern part of the state. Laird said that about 95 percent of all caves are formed from limestone, which is abundant in Iowa. Caves are formed when water dissolves away the rock to create crevasses and caverns. That water, mixed with limestone, leaves behind calcite, which forms into the recognizable shapes of stalactites, stalagmites and columns in caves.

“Water has everything to do with a cave,” Laird said. “Making the rock at the bottom of a shallow sea, then years later, it dissolves that rock and forms a cave.”

The nearest commercial caves that people can visit are in northeast Iowa, southern Minnesota and parts of western Wisconsin, according to Laird. There are also many caves in southern Missiouri. Those caves are often formed in karst regions, which have thin soil on top of limestone bedrock that slowly leaks water to dissolve the rock to form caves. Laird said that Hamilton County sits on a lot of limestone, but lacks the thin soil needed to create those caves.

Visitors to Laird’s presentation will be able to feel what it’s like crawling through a tight space in a cave. He said he has a large plastic tube with a tarp to experience what cavers have to do to traverse caves. He will also bring his own caving equipment to show and explain what is needed to safety go caving. He will also discuss the human impact on karst regions. Larid said that contaminants in the water, or throwing garbage into sinkholes, will go directly into groundwater sources.