During the filming of one episode, Lorne Greene was required to jump off a small ledge into a lake five feet below. Michael Landon later recalled that when Greene did the stunt, he jumped into the water feet first and went completely under, but his hair piece came off and floated on the surface of the lake. Landon and the rest of the crew watched to see what would happen. After a short while, Greene's hand shot up out of the water, grabbed the hairpiece, and pulled it down. Greene emerged from the lake, wearing his hairpiece slightly askew. He walked nonchalantly past the snickering crew, and went into his trailer without saying a word.
When Dan Blocker died unexpectedly shortly before filming began for the final season, it was decided to have Hoss die, too, by having him killed in an accident. The opening episode, a two-hour special in which Little Joe marries only to see his bride die, was originally scripted to feature Hoss.
Most viewers have only heard the famous theme song by Jay Livingston and Ray Evans played as an instrumental. The theme song actually had lyrics and there is footage of the lead actors singing those lyrics. Lorne Greene, Dan Blocker and Michael Landon sang a lyric version of this famous instrumental theme for the pilot, but it never aired. Johnny Cash recorded his own version of the theme song.
According to David Dortort, Michael Landon grew difficult during the last five seasons the show ran: "Nearly every line, every scene, every set up . . . everything would halt for endless story conferences on the set . . . it got increasingly bitter toward the end."
According to the 1973 book "Marilyn Beck's Hollywood", when Pernell Roberts told Lorne Greene he was leaving the series because he wanted to challenge himself as an actor, Greene told him to stick to it as he would be so rich by the end of the run he could hire Tennessee Williams himself to write a play for him. Roberts' career went into a tailspin that lasted over a decade after he left the show. Co-star Michael Landon later said of Roberts' departure that they simply took a leaf out of the dining room table and split the money three rather than four ways. While the post-"Bonanza" Roberts struggled (until later catching on with Trapper John, M.D. (1979), Greene, Landon and Dan Blocker became very wealthy from their income from the show, which all three wisely invested in.
Saturday=night ratings were dismal and the show was soon targeted for cancellation. Given one last chance, it was moved to Sunday nights at 9:00 p.m. The new time slot caused the series to soar, and it eventually reached #1 by the mid-'60s.
Dan Blocker owned a chain of restaurants called "Bonanza". They were steakhouses similar to the "Golden Corral" chain. When the ownership later changed, all of the restaurants were later renamed "Ponderosa".
In the show's early episodes the writers would typically have the Cartwrights being hostile to visitors to their property. Lorne Greene objected to this, pointing out that with the Ponderosa being as large as it is, the Cartwrights would be an important business interest in the community. Thus visitors would naturally come for economic and political reasons as well as social ones and the Cartwrights would logically welcome them as such. The producers agreed and altered the premise of the characters accordingly.
In 1968 Dan Blocker began wearing a toupee on the series, as he was approaching 40 years of age and beginning to lose his hair. He joined the ranks of his fellow co-stars Pernell Roberts and Lorne Greene, both of whom began the series with hairpieces (Greene wore his modest frontal piece in private life, too, whereas Roberts preferred not wearing his, even to rehearsals/blocking). Michael Landon was the only original cast member who was wig-free throughout the series, as even Victor Sen Yung's Hop Sing wore an attached queue (ponytail).
The last 14 episodes of Season One and the first 17 episodes of Season Two have fallen into the public domain. These 31 episodes have been released by many different companies in many different configurations, usually with the familiar theme music replaced with generic music. Starting with episode 1.19, the 31 episodes in order are: "The Gunmen", "The Fear Merchants", "The Spanish Grant", "Blood on the Land", "Desert Justice", "The Stranger", "Escape to Ponderosa", "The Avenger", "The Last Trophy", "San Francisco Holiday" (aka "San Francisco"), "Bitter Water", "Feet of Clay", "Dark Star", "Death at Dawn", "Showdown", "The Mission", "Badge Without Honor", "The Mill", "The Hopefuls", "Denver McKee", "Day of Reckoning", "The Abduction", "Breed of Violence", "The Last Viking", "The Trail Gang", "The Savage", "Silent Thunder", "The Ape", "The Blood Line", "The Courtship" and "The Spitfire".
From the third season on, the Cartwrights and nearly every other recurring character on the show wore the same clothing in almost every episode. This was done to cut the cost of re-filming action shots (such as riding clips in-between scenes), as previously-shot stock footage could be reused.
The opening burning map of the Ponderosa Ranch was illustrated without compass points, which caused the map to appear to be incorrectly oriented (i.e., Reno appeared to be west of Carson City_. David Dortort, choosing not to redo the map, added the compass points. Many have suggested that the compass points are pointing in the wrong direction (slightly north-northwest), but in reality the compass points are aligned with Magnetic North instead of True North.
Both Robert Blake and Robert Fuller were considered for the role of Little Joe Cartwright, but lost to Michael Landon. This was because producer David Dortort had mixed feelings about the new, unfamiliar actor auditioning for the part, thinking Landon was way too young to play the role. With the encouragement of his wife, who picked up a publicity still of Landon, Dortort changed his mind and gave Landon the role.
For a long time producer David Dortort refused to allow Michael Landon to write scripts for the show. It took many failed attempts by Landon before he eventually submitted a script that Dortort thought good enough to make. After this he became a regular writer for the series and later would re-work many of his scripts for new episodes of Little House on the Prairie (1974).
Bonanza was not the first television western series to be completely shot in color as stated elsewhere. That honor goes to The Cisco Kid (1950 - 1956). Bonanza was the first "network" television western to air completely in color.
After 11 seasons the show's theme music was replaced at the start of Season 12 by an original tune composed by David Rose. Rose would continue to work with Michael Landon after "Bonanza" ceased production by becoming the resident composer on Landon's two later series "Little House on the Prairie" and "Highway to Heaven".