In the crack, McConnells Mill State Park by Paul Heckbert

Rim Road climbing area, McConnells Mill State Park, 45 minutes north of Pittsburgh Pennsylvania.

Some geology: before 140,000 years ago, rivers in this area flowed north toward what is now the Great Lakes. During an ice age, lakes built up along these rivers behind the glaciers that covered much of North America. One of these lakes rose enough that it spilled over a watershed divide near here and started to drain south. In a dramatic geologic change, the drainage of several huge lakes over a short time scoured a gorge over 400 feet deep here, resulting in the current Slippery Rock Creek. This creek today flows south and west toward the Mississippi River.

more geology: www.dcnr.state.pa.us/topogeo/ParkGuides/pg4_9/glacial.aspx 
park info: www.dcnr.state.pa.us/stateparks/parks/mcconnellsmill.aspx 
another gigapan nearby: share.gigapan.org/viewGigapan.php?id=30071
if the spherical projection and bent trees bother you, click on the "View in Google Earth" link