Longtime Gold Rush EP Christo Doyle announced on Twitter that today is his last day with Discovery Communications:

Doyle, who is VP production and development at Discovery Channel but may be better known to Discovery viewers for the three seasons he hosted Gold Rush’s popular pre-show The Dirt, tells Deadline his contract is up. In fall of 2015, Discovery decided to end Doyle’s run as The Dirt host, re-casting the role with American Idol competitor turned professional TV personality Matt Rogers. After one season it was canceled.

Doyle was executive producer for most of the first six seasons of Gold Rush, which is the network’s highest rated program. “No one knows the core Discovery viewer like I do – I learned the hard way!” Doyle joked. “I have been privileged to work on incredible shows with the best people in the business.”

During his run at Discovery Communications, Doyle developed and produced programs not only for Discovery Channel but also for TLC, Animal Planet, Travel Channel, and Investigation Discovery, among others. Titles on which he has served as EP include American Chopper, Jungle Gold, Monster Garage, Miami Ink, and Dirty Jobs.