Pirates on the Ohio River?

I've been doing some research on different topics hoping to get some ideas for another book series and I came across this interesting piece of information. There were actually River Pirates here in America!!  I don't know why but the thought of pirates on rivers made me chuckle.  However, once I found out a bit about them, I realized they were no laughing matter.

As early as 1802, pirates began accumulating on the Ohio River with the express intent of relieving settlers passing in flatboats of all their goods and money. Because the Ohio spilled into the Mississippi River which led as far south as New Orleans, it was a popular way to travel long distances for many families. Before the invention of the steam ship, people would hire flat boats which were nothing more than huge rafts to carry them and their possessions down stream with the current. 

The River pirates would hide out in the forest along the water and lure the unsuspecting settlers in by pretending to have supplies and food for sale or by pretending to be injured and in need of help. They often put their women out on rocks by the shore, begging passersby for a ride on their boat. Once the kind settlers reached the shore, they were killed, their bodies dumped in the river and all their goods taken.

Actual picture of inside of the Cave

These pirates eventually had a hideout along the river called Cave-in-the-Rock.  This fifty foot high cave was surrounded by dense woodlands and sat high upon a cliff, affording the pirates a good view of the river. It soon became a true den of iniquity filled with alcohol, prostitution, gambling and pirates. Three notorious pirate gangs were known to inhabit Cave in the Rock during its short history: The Jim Wilson Family, The Mason Gang, and the Harpes. The Harpes were the worst of these gangs who killed people simply for the sport 

Actual picture of outside

Pirating continued from Cave-in-the-rock until 1816 when steamships began to traverse the river in full force. With too many passengers to resist and traveling at faster speeds, the steamboats discouraged the pirates from taking the risk and eventually they gave up and deserted their hideout. By 1818 Cave-in-the-rock was deserted.