Stop #3: Roadcut underneath I-35, near Falls Creek Assembly & on Hwy 77-D, South. I-35 passes over state highway 77-D just south of the Turner Falls exit. The actual cut is on 77-D and runs about 1/4 mile east and west of I-35. Roadcut on the west side of I-35 is Devonian/Silurian limestone. It is slightly yellowish in color and contains trilobites, crinoids, brachiopods, etc. GPS waypoint "OK2".