The AT&T Long Lines microwave relay network provided long-distance transport services from the late 1940s to the early 1980s. By the 1970s, Long Lines carried 95 percent of all long-haultelevision traffic and 70 percent of intercity telephone calls in the US.
By the 1980s, alternatives were replacing microwave as the preferred network transport, but the remnants of the Long Lines microwave network can still be seen across the country-side today, in the form of abandoned relay towers, or towers being employed for other purposes. The new tenant on this site required removal of the horn to make room for their cellular antenna.
Albert LaFrance has an excelent site with more information on these sites -
http://long-lines.net/
