The "knobs" on the stone blocks discussed in this video are from the casting process used to make the "stones". Many (most?) of the blocks weren't quarried, they were cast in place using a lost technology . . . SC]

Deep in the remote mountainous wilderness of Montana, we find this remarkable structure known as the Sage Wall. This imposing megalithic wonder is composed of massive polygonal granite stone blocks intricately stacked and aligned in a perfectly straight line. The Sage Wall's unique features, such as its straight lines and angular formations, set it apart from the natural geological formations commonly found in the region, connecting it with other sites commonly known as the Montana Megaliths. https://www.youtube.com/watch?v=neOHDmmYFdk&t=488s