Fallon asks Dex what he knows about the man - made lake .
Dex vaguely mentions that Dex was used to flood an abandoned mine on the property following a failed business deal between the Colby , Carrington , and Dexter families : Colterton Mines .
Fallon asks Dex what he knows about the man - made lake , and Dex vaguely mentions that it was used to flood an abandoned mine on the property following a failed business deal between the Colby , Carrington , and Dexter families : Colterton Mines .