McConnells Mill Area
The trail from the picnic grounds to the mill, the road past the mill, and the trail to Alpha Falls, all cross outcrops and slump blocks of the Homewood Sandstone. Note the separation along vertical cracks, the downslope rotation of some blocks,
and the crossbedding and pebbly composition of some layers.
A honeycomb pattern has also formed on a few weathered surfaces. This forms when groundwater moving through the rock deposits iron minerals that are more resistant to weathering than the surrounding rock. The iron minerals stand out when the rock is weathered.
At the Rim Road Climbing Area, large blocks of Homewood Sandstone have separated from the outcrop and slumped downslope to create open walkways and a spectacular “rock city."
The north exit road from the mill passes through a similar rock city.
The intact ledges at the mill dam are at the top of the Connoquenessing Sandstone, about 40 feet below the base of the Homewood, and directly beneath the Mercer shales and coals (see cross section in bedrock section).