"The traveler on the journey from Ogden to Montana Territory, if he will watch the western horizon, while crossing the Great Lava Plains of Snake River, is almost sure to witness one or more of these optical delusions of nature. They are of great variety, and occur principally in the morning, soon after or about sunrise, and late in the afternoon…. The mirage represented in the plate is the Three Buttes, changed in form -- two of them representing huge buildings with perfectly straight walls, towers and regularly sloping roofs; one of them having a singular shaped cap on the comb of the roof."