4. Five-sixths of the total area of the Republic is covered with a forest, dense even for the tropics. Almost everywhere this forest comes close down to the sandy beach and the impression made upon the traveler who sails along the coast is one of perpetual verdure. The highest lands are found in the east half of the country. In the region of the Upper Caballa River just outside of Liberia, French authorities claim that Mount Druple rises to a height of 3000 meters. The same authorities claim that the highest point of the Nimba Mountains, which occurs within the limits of Liberia, is about 2000 meters (6560 feet). Further south is the Satro-Nidi-Kelipo mass of highlands bordering the Caballa basin on the southwest; Sir Harry Johnson claims that it offers nothing more than 4000 feet in height. Northeast of the Caballa are Gamutro and Duna which rise to 5000 feet. There are no heights comparable to these found in the western half of the Republic, though there are peaks of significance among the upper waters of the St. Paul’s River and its tributaries. In the lower half of this river’s course there is a hilly or mountainous region known as the Po Hills, where possible heights of 3000 feet may be reached. In the northwestern part of the country the forest gives way to the Mandingo Plateau, high grass-land. Benjamin Anderson, a Liberian explorer, says that he emerged from the forest at Bulota where the ground rose to the height of 2253 feet. This plateau region is open park-like country of tall grass with few trees. Very little as yet is known of the geology of Liberia. On the whole, its rocks appear to be ancient metamorphic rocks--gneiss, granulite, amphibolite, granites, pegmatite, all abundantly intersected by quartz veins. Decomposition products from these rocks overlie most of the country. The material and structure of the coast region is concealed by deposits of recent alluvium and the dense growth of forest; a conspicuous lithological phenomenon is laterite which covers very considerable areas and is the result of the disintegration of gneiss. As yet little is known of actual mineral values. Gold certainly occurs; magnetite and limonite appear to be widely distributed and are no doubt in abundant quantity; copper, perhaps native, certainly in good ores, occurs in the western part of the country; various localities of corundum are known, and it is claimed that rubies of good quality have been found; companies have been organized for the mining of diamonds, and it is claimed that actual gems are obtained.