From a history of early Wyoming:
"Another early important historic landmark in Daniel was Ft. Bonneville named for Captain Benjamin L.E. Bonneville of the U.S. Army. Nothing is left there today but in 1915 one could still see rotten stumps. It was built in 1832 for temporary protection for his men, though it wasn’t a good location. (Trappers called it "Bonneville’s Folly" and "Fort Nonsense.") There was no real protection there from Indians or the weather. Fear of being snowbound, Capt. Bonneville evacuated it just when finished! It was the first fur fort in what is now Wyoming. Bonneville only returned briefly the next summer for the rendezvous."
Historians, like Bernard DeVoto, believe Bonneville built his fort in the ideal location to help the US capture Oregon. It was perfect to monitor the British, Spanish and Russians, all attempting to make claims in the US West.
Lots of mosquitos were there.