usora is left tributary of the bosnia in central bosnia. the total length of the river usora – from sources below the top of the mountain očauš to the mouth above the doboj is about 82 kilometers. the town of teslić, through which it flows, bears the local name velika usora (great usora), since under the city at a place called sastavci meets with his same named, but a lot less left tributary mala usora (little usora). it also comes from the mountain masiff uzlomac – borja – očauš below it in smaller distances rises more bosnia river and their tributaries, as well as the basin vrbanja river and ukrina. in its upper reaches, the river makes a wide loop around borja, from its southwest to northeast slopes.