It was the same in Britain at that time, with local routing codes being used extensively. Small exchanges serving villages and rural areas (referred to as dependent exchanges) dialed 9 to reach their parent office, and callers on the latter would dial two-digit codes to reach those outlying places, most commonly 8x, but sometimes other combinations such as 5x, 6x, or 7x.
Calls from one dependent exchange to another within the area used the parent exchange as a tandem, with listed codes which made the routing perfectly obvious, e.g. dial 983 plus the local number.
Trunks between the parent exchange and its counterpart in a neighboring area were accessed with more codes, typically 9x. These outgoing trunks were made accessible from incoming trunks so that the dependent exchanges could "dial through." Thus a call from a dependent exchange in one area to a dependent exchange in an adjoining area would result in two tandem exchanges and a listed routing code which was quite long, e.g. 99182, in which the first 9 routes to the parent exchange, 91 selects a trunk to the neighboring area, then 82 routes to a dependent exchange (and the chances are that after all that the local number in that tiny office would be only three digits long!).
Just to complicate matters further, if there was sufficient traffic between two points direct trunks could be installed and a completely separate direct routing code added, sometimes just a single digit on a spare first level (e.g. "For calls to ______, dial 6 plus the number").
The way that the routing codes varied from one office to another meant that dialing cards or booklets were issued separate from the phone books instructing callers how to dial nearby places from their phone.
Of course, armed with a whole batch of such cards from the area, it wasn't difficult to map out almost the entire system of routing codes and figure out ways of routing calls which were not officially sanctioned. In fact in some cases it allowed a call which should have been charged at long-distance rates to be placed as a local call.
These local routings survived right up until the 1980s.
-Paul.