Features
Kansas and Nebraska byways: limestone, chalk and the signs that mark them
Limestone in the Flint Hills, Niobrara Chalk near Monument Rocks and Sandhills sand: which Kansas and Nebraska byway signs name each rock and where to pull over.
What to take away
- Kansas and Nebraska scenic byways carry two rock storiesPermian limestone in the Flint Hills and Cretaceous Niobrara Chalk in the west.
- The Flint Hills Scenic Byway follows K-177 between Council Grove and Cassoday, where road cuts show layered limestone and chert.
- Monument Rocks, Castle Rock and Little Jerusalem Badlands State Park are the main Kansas chalk stops.
- Toadstool Geologic Park, Ashfall Fossil Beds and the Niobrara River valley hold the Nebraska chalk and ash stops.
- The Sandhills Journey Scenic Byway runs on Nebraska Highway 2 across grass-stabilized dunes.
Flint Hills limestone and post rock country
The Flint Hills Scenic Byway runs along K-177 from Council Grove south to Cassoday. The route crosses the last large block of tallgrass prairie in North America. Road cuts beside the highway expose thin beds of Permian limestone separated by chert, the flint that named the hills.
Chert resists weathering, so it caps ridges and keeps slopes steep. That is why much of the Flint Hills was never plowed. Interpretive signs at Tallgrass Prairie National Preserve near Strong City name the layers as limestone and chert, not granite.
Northeast of the Flint Hills, the Native Stone Scenic Byway follows Kansas 4 and Kansas 99 through Shawnee, Douglas and Osage counties. Settlers split Fencepost limestone from the Greenhorn Limestone into fence posts and barn walls because trees were scarce. Those stone fences still line the road.
| Byway | Rock named on the route | Place to pull over |
|---|---|---|
| Flint Hills Scenic Byway, K-177 | Permian limestone and chert | Tallgrass Prairie National Preserve |
| Native Stone Scenic Byway, K-4 and K-99 | Fencepost limestone | Stone fences and barns near Alma |
| Gypsum Hills Scenic Byway, US-160 | Gypsum and red shale | Gypsum Hills Scenic Overlook |
| Sandhills Journey Scenic Byway, N-2 | Grass-stabilized sand | Nebraska National Forest at Halsey |
| Bridges to Buttes Byway, US-20 and NE-71 | Brule Formation chalk and ash | Toadstool Geologic Park near Crawford |
Chalk badlands in Kansas and Nebraska
Niobrara Chalk is a Cretaceous marine deposit built mostly from coccoliths, the plates of microscopic algae, plus shell debris. It erodes into white spires and narrow gullies. In Gove County, Kansas, Monument Rocks National Natural Landmark rises from ranch land at the end of a gravel road off US-83.
Little Jerusalem Badlands State Park in Logan County protects a larger chalk canyon system. Access is by guided tour only, because the chalk crumbles easily. Castle Rock, also in Gove County, stands beside a county road near Quinter.
The chalk continues north along the Niobrara River near Valentine, Nebraska. Fort Niobrara National Wildlife Refuge and Smith Falls State Park sit on that stretch, where white bluffs rise above the water. Toadstool Geologic Park near Crawford exposes a younger Brule Formation chalk and volcanic ash.
East of Crawford, Ashfall Fossil Beds State Historical Park near Royal preserves rhinoceroses, horses and camels buried in ash from an eruption far to the west.
What the byway sign actually says
The Manual on Uniform Traffic Control Devices sets lettering, color and shape rules for guide signs on public roads. Brown guide signs mean recreation and cultural interest, so a byway marker is a brown panel with white text. It usually sits above a state route shield and an arrow.
The National Scenic Byways Program lists national designations and the criteria a route must meet. States post the markers and run their own systems, and the scenic byway concept explains how a road earns one.
Example: reading a Kansas chalk pull-off sign
Reading a Kansas chalk pull-off sign
- Read the byway name on the brown sign and note the route number below it.
- Match the name to the rock unit. Flint Hills means limestone and chert; Gypsum Hills means gypsum and shale.
- Look for a state historical marker at the pull-off, since Kansas and Nebraska both post them at geological and trail sites.
- Check the road surface before turning off, because Monument Rocks and Toadstool sit at the end of gravel roads.
Niobrara Chalk holds the remains of mosasaurs, plesiosaurs and flying reptiles, and it drew fossil collectors to western Kansas in the 1870s.
Granite, volcanic and red rock routes for comparison
The Flint Hills and Niobrara cuts are sedimentary rock. Bend and Rapid City byways make a useful contrast, because Cascade Lakes Scenic Byway near Bend crosses volcanic rock while Black Hills routes out of Rapid City cut granite.
Three signed red rock byways out of Moab and Santa Fe run on sandstone and mudstone, and that page lists the agencies that post and maintain each marker.
