a surrogate mother figure to fill the void left by the death of Bea Benaderet, and takes up a medical practice at the hotel and also serves as a counsel of sorts for the girls. The cast was described as "most welcoming" to Lockhart as the newcomer during a difficult time. Quickly, Lockhart graduated from featured billing at the end of each episode to co-star billing in the opening credits. The show's theme song lyrics were slightly altered to accommodate the change in cast. A decline in Nielsen ratings had begun in season five, when CBS moved the show from Tuesday night to Saturday night. In season six, the show failed to make the ratings top 30. With Benaderet's death and the mediocre ratings, the sitcom's future was hanging in the balance. CBS considered cancelling the show in the spring of 1969. The season-six finale "Tune In Next Year" was meant to be the series finale. Dr. Janet Craig receives a good job offer in another city and decides to accept it. However, at the end of the episode, Dr. Craig decides to stay when Steve and Betty Jo announce that they are going to have another baby. At the last minute, CBS decided to renew the series for a seventh season. The main reason for the renewal was that it would give the series five full years of color episodes for syndication, which would be very profitable for the network. When the show returned for its seventh and final season in September 1969, two major plotline changes were made. The first is that Steve and Betty Jo, and their daughter Kathy Jo, move out of their cottage and back into the Shady Rest Hotel. The storyline involving Betty Jo's new pregnancy was dropped and never referred to again. The second change is the addition of bumbling, but well-meaning, game warden Orrin Pike (played by actor Jonathan Daly), who becomes Bobbie Jo's boyfriend, much to the annoyance of Uncle Joe. In the spring of 1970, despite somewhat improving ratings, Petticoat Junction was cancelled as a precursor to the CBS rural purge of the early 1970s, when all rural-themed shows were cancelled. Its final first-run episode was broadcast on April 4, 1970, and the series officially ended its primetime run on Saturday, September 12, 1970, at 9:30 pm. It was replaced one week later by The Mary Tyler Moore Show.Petticoat Junction