Wall Number | Country | State Sort descending | Classification | Source |
---|---|---|---|---|
9LB14 | United States | Iowa | Limestone | Fairfield |
12LB30 | United States | Pennsylvania | Marble | Avondale |
7La13 | United States | Pennsylvania | Limestone | East Conshohocken |
8Lb46 | United States | Washington | Sandstone | Pittsburgh |