In 1974-75 I was a Lt(jg) in the Coast Guard assigned to the District 12 engineering office in San Francisco and was given the job as project engineer for the buildings and site work for 2 stations as part of the West Coast/Gulf of Alaska chain. Ours were located at Middletown CA 80 miles north of San Francisco and at Fallon, Nevada, 50 miles east of Reno. The Fallon station was especially interesting since it was situated in the Carson Sink area where the Carson and Truckee rivers flow east out of the Sierra Nevadas and disappear into the desert. It was flat and covered with powdery alkali soil with sparse chaparral. The water table was near the surface so there were a few alkali pot-hole ponds that were home to the most aggressive and hungry mosquitos I have ever seen. As I recall the crew was about 5 or 6 people, mostly Electronics Techs with a Warrant Officer CO. I always wondered what the reaction was to some young Coastie who ended up in a setting from an old Wagon Train show.

I was not involved in the electronics side of things but we did erect the 600 ft antennas that transmitted at 100khz That is well below the bottom end of the AM radio spectrum at 535khz. By tuning an am radio to the bottom frequency you could usually pick up a harmonic which made a zzzt-zzzt-zzzt sound on the radio. The original transmitters installed used vacuum tubes about the size of a watermelon. No doubt those were later changed out for something solid state. Everything except the antennas could be repaired or replaced on site in a few minutes.

The other stations in our project were located at:
Searchlight NV (near Las Vegas)
George, WA (near Martha, WA in central Washington State)

The chain included 3 stations in British Columbia and one near Fairbanks AK.

Below is a link to a pretty good Wikipedia article.