Though news broke a few days ago that AMC had officially renewed Hell on Wheels for a third season following high ratings and tons of critical acclaim, it looks like that may not be the case. According to Deadline, there's a bit of behind-the-scenes drama going on between writers and the network, AMC, and it looks like creators/executive producers Joe Gayton, Tony Gaton, and showrunner Joe Shiban have all departed from the series. A third season is now dependant on the network hiring a new showrunner to take Shiban's place, so the renewal has been put on hold for the time being.
In a statement, AMC addressed the departures, saying:
John Shiban has informed AMC, Entertainment One and Endemol that while he was fully on board when the network informed him about their intent to pick-up Hell on Wheels, he has since made the personal decision that he will be unable to return as showrunner. He has asked the production partners to seek a replacement showrunner. Like all of our shows, network pick-ups are always conditioned on an approved showrunner. We are confident that eOne and Endemol will satisfy that obligation in the near future.
Addtionally, Shiban commented on his leaving the show in a statement of his own, assuring fans that he cares "deeply about the series and will do whatever I can to aid in the transition to ensure the continued success of the show."