Below is a clickable image map of the Sidamo mountains, with the names of the principal tribes and their area of influence indicated. The Tigara, the Hamma and the Harrar are of the race generally called Kvarch-nari after the ancient city of the same name, while the Kanakil and Gallara are rcent invaders of Keshite stock, who have come over the mountains from the east. Kvarch-nari are generally dark-brown-skinned with curly black hair. The men normally grow beards. The Keshites are stockier, with frizzy hair, and generally litte facial hair. Their skin is much darker. You can read more about the various tribes here.
The Sidamo mountains soar over 2000 metres, but the hot, dry climate means they very rarely have snow on their peaks. The water dumped by the occasional storm, swells the rivers which drain the mountains to flood point and is quickly absorbed by the thirsty soil. Otherwise the mountains are a mass of sere, knife-edged crags, dotted with a few eyrie villages and even fewer, inaccessible and rarely-visited cities. The people of the adjacent Martic lands know little of the Sidamo mountains and populate them in their stories with savage tribes and fierce monsters - in which they are largely correct. The mountains are important largely because the activities of the piratical Red Brotherhood and the human-sacrificing Wyvern Riders have made the passage of the straits of Tarek into the Mithil Sea very dangerous. Goods to and from the Empire of Saharn and the city of the Artificers of Penume therefore often go overland from the southern Martic lands over the Bakaka pass and out through the port of Irilian, despite the risk of attack by mountain tribesmen and the long distance. Even the flying dragon-ships of the Artificers of Penume do not care to dare the treacherous airs of the Sidamo without good reason.
However, the mountains draw a steady trickle of adventurers. There are rumours that the ancient cities of the mountains date from earliest antiquity and that there are vanished temples and abandoned fortresses in mountain fastnesses that hide fabulous treasures. Enough loot does trickle down from the mountains to lend some credence to the rumors, but most treasure-hunters are swallowed up by the dry brown wilderness and are never heard from again.