The only Flintstones episode where Bedrock has a "subway" line. One of the stations is called "Pebble Street"
The last episode where we hear of the "Loyal Order of Dinosaurs". The following seasons, the club is renamed the "Loyal Order of Water Buffaloes".
ABC originally broadcast this episode in black and white.
The amounts of the "checks" Fred is counting at the beginning of the episode: $117.00 + $62.50 + $41.75 + $11.82 + $26.70 = $259.77.
The calendar on which Fred crosses out the days shows May 17th as falling on a Wednesday. In 1961, May 17th really was a Wednesday.