These Hills of ours
Field Notes
~ by Jim Eagleman“ The hills o’ Brown go up and down …”— Anonymous
Brown County is known for its vast forest lands covering rugged landscapes. You might wonder why our terrain is so varied.
Long roads along a ridge with steep slopes on either side weren’ t just constructed for the view— although that’ s a nice benefit. Ridgetop roads are the most effective way to travel. You may notice you are going out of your way, but it minimizes up and down routes.
Maintaining graveled roads is a constant task. We’ ve all experienced the head-bouncing, washboard rattle as we drive a recently washed-out road. New gravel must be added at times and redistributed to keeps things safe.
This rugged landscape started out a long time ago. Geologists tell us it was during the Cambrian period, some 480 million years ago, when shallow seas covered much of the southern part of the Midwest. Indiana was close to the Equator back then. It takes a bit of thinking and imagination to picture this.
I have always wondered why our county is so well covered with sandstone, while just to the west is Monroe County, known for its limestone. The limestone was laid down during a period of wide-area shallow seas composed of marine or salt water. Fresh water aided in the deposition of the Brown County sandstone whereas the saltwater environment produced the limestone— an interesting phenomenon.
Sandstone comes from sand being layered over time. In ancient times, the sand’ s origin, some theorize, was in the fresh water from what was to become the Great Lakes to the north, or from the young Appalachian Mountains to the east. It settled into what was called the Illinois Basin.
More rugged in their younger years, the eastern mountains sloughed off surface material that washed into this lower area. During dry periods, sun and heat compressed the layers of sand. You can see these layers when you pick up a piece of sandstone. There can be several shades of browns and tans, some thicker than others. Since it is sand, it is easily worked by wind, rain and weather. It becomes brittle, and may be why so many odd shapes outcrop on the sides of hills.
Fresh water animals and plants lived in this environment, but very little remains in the fossil record. We do find crinoids that could actually move around and filter food in the water. Their segments of stems appear like little stacks of Cheerios, or“ Indian beads” as some call them.
Contrast this county with nearby Monroe County with Bloomington’ s quarries of exposed limestone and nearby Bedford in Lawrence County,“ the limestone capital of the world”.
60 Our Brown County March / April 2026