At the foot of mountain ranges these alluvial cones are formed at the mouth of every ravine, and are sometimes so near together that they intersect each other, or become confluent. They are composed of rudely stratified materials, ranging in size or grain from fine silt and sand to rounded stones of several hundredweight, and occasionally a block of a ton or more may be seen near the apex of the cone. In regions where the rocks are soft and readily disintegrated the stones are more worn, less in number, and smaller in size, and this is the case generally with unaltered sedimentary rocks. But in valleys running among volcanic ranges, the much greater hardness and durability of the materials preserve them from disintegration, and the stones are more numerous, larger, and less worn by attrition, composing indeed a very large proportion of the bulk of the alluvial cones. A large portion of the valley of the Sevier lies in the midst of a volcanic region, and its sides are everywhere flanked with these alluvial cones, which are very stony and gravelly. The lower portion of the Sevier is in a country made of sedimentary beds, and though the alluvial cones are equally common, they consist of finer material, and are less burdened with stones. The Panguitch Valley is between volcanic plateaus, and most of its area consists of alluvial cone land, which is no doubt fertile wherever the stones and rubble are not sufficient to prevent plowing and planting, but this difficulty must render it at least very undesirable. There is, however, a large area of land of another description in Panguitch Valley, composed of the finest silt brought down by the gentler current of the river itself, and deposited within its own basin. This is good bottom land, and the amount of it I estimate at not less than 7,000 acres. It has already been remarked that Panguitch Valley stands at an altitude above 6,000 feet, and is not free from danger of summer frosts. These have been known to destroy or seriously injure the grain, though in a majority of years crops will no doubt be safely harvested. Whether the danger is such as to make agriculture unremunerative in the long run experience can alone demonstrate.