Deadwood

Despite appearing in 32 out of 36 episodes, Jeffrey Jones (Merrick) was listed as a guest star in the first season. Similarly, Gerald McRaney (George Hurst) received a "special guest star" credit in Season 3, even though he appeared in all 12 episodes of that season.

For a long time there was a bar called Bullock's Tavern in Amherstburg, Ontario, Canada, which was originally owned by Seth Bullock's parents and was also the place he was born.

HBO offered the chance to David Milch to wrap the series in a shorter four season, but he declined to do it on those conditions. However, when Chris Albrecht was asked about it, he said that they also told Milch that HBO would give him a full 12-episode season if it was what he needed to wrap the show. Milch told them he would think about it over a weekend, but the news about the show possibly being cancelled reached the press to such a speed that that conversation never happened