Saw a place that had what appeared to be a RV carport type of "building" on 131 headed south out of Petoskey last Friday. looked like aluminum or steel posts (about two inches square) and a rounded top. Know that doesn't help much with the where, but suggests they are made. All you have to figure is how to google it to get some manufacturers.
Pole barn type structure, without sides might be more structurally sound against windy conditions.
Dave and Beth
2015 Cornerstone 45J
Ford F-150 and 2016 Polaris Razor