The burning map in the opening scene is actually the eastern shore of Lake Tahoe and not the northern shore. This can be proven by turning the image 90-degrees clockwise and comparing it with a map. The burning is symbolic of cattle branding irons.
You and your education.
Adam Cartwright: Education is progress! Now what have you got against it?
Ben Cartwright: I don't have anything against education - as long as it doesn't interfere with your thinking!
Floor model wheel slot machine in saloon was not built until 1896.
In the opening sequence, when the actors ride on their horses towards the camera and are introduced, the order in which they are introduced is never consistent - this was most likely done to prevent a single actor from becoming the "main" star of the show.
Many television broadcasts and DVDs of public domain episodes currently in circulation replace the famous title theme music with generic music. Only official videos and DVDs from Artisan/Republic are uncut and contain the music as intended.