 | Mammoth Cave Saltpeter Works,Mammoth Cave,Edmonson County,Ky,Kentucky,Habs,15 |  | $13.59 | $10.87 | | US | 19d 3h 21m |
 | Mammoth Cave Saltpeter Works,Mammoth Cave,Edmonson County,Ky,Kentucky,Habs,31 | | $13.59 | $10.87 | | US | 19d 3h 21m |
 | Mammoth Cave Saltpeter Works,Mammoth Cave,Edmonson County,Ky,Kentucky,Habs,20 | | $13.59 | $10.87 | | US | 19d 3h 21m |
 | Mammoth Cave Saltpeter Works,Mammoth Cave,Edmonson County,Ky,Kentucky,Habs,25 | | $13.59 | $10.87 | | US | 19d 3h 21m |
 | Mammoth Cave Saltpeter Works,Mammoth Cave,Edmonson County,Ky,Kentucky,Habs,8 | | $13.59 | $10.87 | | US | 19d 3h 21m |
 | Mammoth Cave Saltpeter Works,Mammoth Cave,Edmonson County,Ky,Kentucky,Habs,12 | | $13.59 | $10.87 | | US | 19d 3h 21m |
 | Mammoth Cave Saltpeter Works,Mammoth Cave,Edmonson County,Ky,Kentucky,Habs,28 | | $13.59 | $10.87 | | US | 19d 3h 21m |
 | Natural Bridge Virginia Va Postcard 1930-1950 Salt Petre Cave | | $8.14 | $3.06 | | US | 19d 3h 50m |
 | Natural Bridge Virginia 1940S Postcard Salt Petre Cave | | $4.12 | $4.08 | | US | 19d 4h 36m |
 | 1930'S 1940'S 1950'S Salt Petre Cave National Bridge Virginia Va Postcard Peter | | $5.75 | $ | | US | 19d 4h 46m |
 | Postcard Saltpeter Cave Waterfalls Montserrat | | $13.59 | $16.39 | | US | 19d 8h 27m |
 | Saltpeter Saltpetre Leaching Vats In Mammoth Cave Park, Kentucky Postcard Unused | | $8.15 | $14.72 | | US | 19d 13h 39m |
 | Natural Bridge, Virginia, Va, Salt Petre Cave, Linen Vintage Postcard B548 | | $2.72 | $17.28 | | US | 19d 15h 3m |
 | Vintage Postcard~Natural Bridge, Va~Salt Petre Cave~Man & Woman On Wooden Bridge | | $8.15 | $2.72 | | US | 19d 17h 16m |
 | Postcard Salt Petre Vats Operated During War Of 1812 Mammoth Cave Ky Unposted | | $6.80 | $ | | US | 19d 20h 28m |
 | Vtg Kentucky Ky Salt Petre Vats Mammoth Cave National Park 1940S View Postcard | | $5.43 | $2.04 | | US | 19d 21h 21m |
 | Assorted Cds~Make Your Own Lot~Pick Just One~Multiple Genres~Rock/Pop/Alt!!! | | $9.52 | $ | | US | 19d 23h 0m |
 | Salt Petre Cave, Natural Bridge, Virginia Postcard | | $10.57 | $14.79 | | US | 20d 3h 34m |
 | Old 8X6 Historic Photo Of Saltpeter West Virginia The Railroad Station C1930 | | $8.19 | $0.91 | | AU | 20d 5h 23m |
 | Chile Scrip Nitrate Bill Oficina Sacramento 5 Pesos 1920S Saltpeter Salitre Vale | | $25.78 | $5.37 | | MX | 20d 8h 48m |