A Kendal Calling drugs dealer has been jailed for two-and-a-half years.
Carlisle Crown Court heard how Lee Clayton was caught as he tried to deal class A substances to an undercover security officer at the music festival, near Penrith, on 29 July last year.
Clayton, 46, was carrying a "man bag" containing an illegal supply "kit" comprising of cocaine, ecstasy, LSD and class B ketamine, along with "substantial cash reserves".
The total potential street value of drugs found in his possession - and hidden with thousands of pounds inside a camper van on the site - was more than £6,000.
Police also recovered a phone from the vehicle which showed 499 incoming calls on that day alone.
When arrested by police at the festival site, Clayton stated: "I'm here to have a good time."
He admitted possessing all four drugs with intent to supply them, and was jailed by Recorder Kevin Grice this morning.
The judge heard remorseful Clayton, a father with responsibilities to several children, had confessed to making a "catastrophic mistake" at the festival which he would regret "for the rest of my life".
But the judge told Clayton, of Devonshire Drive, Clayton-le-Moors, Accrington: "Only an immediate custodial sentence is appropriate."
Recorder Grice added: "You made, as you acknowledge, a terrible mistake last July."