A four-foot single fiberglass antenna's range should be about 4-7 miles. The two types of antennas with the shortest expected range is the magnetic mounted antenna and the no ground plane (NGP) antenna, which, at four-foot lengths, have about a 3-5 mile range - only about 70% of that of the ground plane antenna.
That's from the Wiki...
Obviously pretty useless by today's standards... but in a time full of repeaters and relays, they made sense.