(the single hoop...)
If you are interested in gear history , take a look here :
http://www.oregonphotos.com/Backpacking ... tion1.html
George replied commenting that when Jack Stephensons started fiddling with a single hoop shelter (not the traditional A frame structure common at the time) he credited the Native Indians for the inspiration.
Here is a pic of the "longhouse" pre-dating the tunnel design and several wig wams pre-dating the geodesic/semi geodesic version "invented" in the 70's ....



Jack started making tents in the late 50's and eventually marketed his 3 pole version , the Model 6 in 1964.
This is a 1961 version

Some may note the similarity with the tunnel design usually credited to another well known manufacturer that started selling theirs in 1981 ...
Franco