this is Sage from his writings.
Preparations for leaving. Scenes at Camp. Things as they appeared. Simplicity of mountaineers. Sleep in the open air. Character, habits, and costume of mountaineers. Heterogeneous ingredients of Company. The commandant. En route. Comical exhibition and adventure with a Spanish company. Grouse. Elm Grove. A storm. Santa Fe traders. Indian battle.
AFTER many vexatious delays and disappointments, the time was at length fixed for our departure, and leaving Independance on the 2d of September, I proceeded to join the encampment without the state line. It was nearly night before I reached my destination, and the camp-fires were already lighted, in front of which the officiating cook was busily engaged in preparing the evening repast. To the windward were the dusky forms of ten or fifteen men, —some standing, others sitting a la Turk, and others half-reclining or quietly extended at full length upon the ground, —watching the operative of the culinary department with great seeming interest.
Enchairing myself upon a small log, I began to survey the surrounding objects. In the back ground stood four large Connestoga waggons, with ample canvass tops, and one dearborn, all tastefully drawn up in crescent form. To the right a small pyramid-shaped tent , with its snow-white covering, disclosed itself to the eye, and presented an air of comfort.
Rufus Sage travelled thru the rockies from 1841 to 1843 however, FoxRiver traders mentions that he stayed in one, I find that nowhere in Sages books. However if what he describes is a pyramid tent as we know it, it's quite possible he had not seen the first of it's kind. Nowhere does it mention a tipi of canvas or a camp using one.