Stargate Observatory was built in 1969 by the WAS and the Rotary Club of Michigan. Dick Polus, then-president of the WAS, was informed of an available observatory site on the Rotary Club Campgrounds by his neighbor, Harold May, who was a Rotary member. The original plan for the observatory was to have a simple building with a roll-off roof. The Rotary members, however, wanted a building with a dome, and offered to help substantially with construction if that design were chosen.
Hofley Manufacturing provided material for the dome framework, and shaped the pieces free of charge. The WAS cut and finished the dome framework over three evenings at Polus's house, then welded it together onsite. Sheet aluminum was cut and riveted to the frame, and placed atop the completed building with the help of member Mel Mazzline. Stargate Observatory went into operation in the Spring of 1970.