This question hits upon the central mystery of the Hanna-Barbera pantheon,
the Holy Grail of discussion among Flintstonephiles. Where does Fred drop
Barney off each morning, where does he pick him up at the end of the
workday, and what does Barney do in between?
At first, it appears that Barney may work at the quarry with Fred, since he
bowls on the quarry's bowling team ("The Flintstone Flyer"). The exact
nature of Barney's next job is unknown, but Fred inadvertenly gets him fired
from it in "No Help Wanted," the 6th episode produced. (Fred explains that
he told Barney to "put his broom down"; Barney later remarks that "it wasn't
much of a job"). Fred then helps Barney secure a job as a furniture
repossessor, but this career is never mentioned again and appears to have
been brief. Other temporary positions include travel agent, co-owner (with
Fred) of "The Drive-In," and (again, with Fred) private investigator.
On one occasion we are clearly shown that he works at Pebbles Co. Rock and
Gravel (which may or may not be a competitor of Slate Rock and Gravel),
though we don't know what he actually does there or how long this job
lasted. At times, one is again tempted to believe he works with Fred in the
gravel pits; he certainly hangs out there a lot. Indeed, Barney briefly
becomes a vice president at the quarry (after once again losing an
unidentified job somewhere else) when he turns out to be related to Mr.
Slate; once again, he does not hold the position long.
But vague, cryptic references to Barney's job are sprinkled throughout the
original series, and at one point Betty (following Wilma's example of using
an impressive euphemism to describe her husband's career) says that Barney
is in "top secret work"--a deliberate nod to curious Barney fans? (Or is
Barney merely unemployed again?)
Series and specials subsequent to 1966 (beginning with the Busch beer
promotional campaign) more or less (though not always) agree that Barney
does, in fact, work alongside his pal Fred at Mr. Slate's. But the nebulous
nature of Barney's job over the course of the original series remains a