My Opinion: My Father-in-law owned a big ranch located just 20 miles east of Yellowstone Park. This area and most of Montana was rich in what has been called Montana Moss Agate. In the 50s around Forsythe, Mt. you could pick up big cobbles almost anywhere in the hills and the big rivers were full of it. The Indians from the sheepeater age on used this agate as their main material for tools and blades. The Chipping grounds were covered with the spalls and chips of this agate. The lava flows that make up a good deal of the local mts. provided the collecting pockets for the formation of the agates and jaspers found here. Mt. moss agate is prized by the jewelery makers for its dendrites. It requires some heat treating to work well and the agate nodes without dendrites makes the best and strongest points. The raw rocks are very spendy and they are not all good knapping material and that is why many of us saw it rather than using percussion techniques. As I recall my life on the ranch, the use of agate for arrowheads was very effective on elk, deer, and bear. This is the truth as I remember it. A/Ho Indian Joe
