Yellow Springs, MD

Also known as Catoctin Mountain

Common Language Location Identifier (CLLI): YLSPMDQ0010

Site Data

FCC Microwave License Data


Yellow Springs consists of a self-supporting steel tower and a concrete-block equipment building in two gable-roofed sections, located among other radio communications facilities in mountaintop "tower farm". The style of the building is typical of AT&T's older microwave and coaxial-cable repeater stations.

Historical Role

Thanks to Terry Michaels for his contributions to this section

Yellow Springs was a relay station on the microwave route between the Garden City station in Arlington, VA and the Clark's Knob station near Upper Strasburg, PA. During at least some of its history Yellow Springs carried only television programming, with its ultimate destinations being Washington, DC and New York City.

The station was constructed in the early years of the Long Lines network, beginning service on September 18, 1950. Articles in the Bell Laboratories Record issues of March 1950 and November 1950 discuss the Washington-New York City route. A U.S. Army Signal Corps memorandum dated 4 May 1951 also mentions the facility.

Initially, the tower at Yellow Springs was equipped with delay-lens antennas, as shown in the 1952 photograph below. This type of antenna, installed on AT&T's early microwave routes, operated only in the 4-GHz band and only handled one signal polarization with six RF channels. The delay-lens antennas were replaced in the 1980s by shielded parabolic "dish" antennas, 10 feet in diameter (bottom row of photos). This change, made at a number of northeastern stations, was due to the problem of moisture accumulating in the polystyrene foam elements of the delay-lens antennas.

The reason for the station's dual names is not known. Long Lines route maps from 1970, 1979, and 1988 identify the facility as Yellow Springs, while the 1966 and 1976 maps, and the Signal Corps memo, call it Catoctin Mountain.

Route Map

Present Function

Yellow Springs is now owned by a tower-site leasing firm, and the tower hosts numerous antennas for various communications services. All of the AT&T microwave antennas have been removed.


Select an image to view a larger version

Photographed March 25, 2001

Photographed March 25, 2001

Photographed March 25, 2001

Photographed March 25, 2001

Photographed March 25, 2001

ca. 1952; from the Bell System Technical Journal, September 1952

Tower in left foreground (with cabin) is Western Union's Gambrill Park microwave station, now owned by the Federal Aviation Administration.
Image courtesy of Terry Michaels

Image courtesy of Terry Michaels

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Updated on March 31, 2004 at 21:56 by Albert LaFrance