the bistra has its source in the bistra lake, located in the țarcu mountains, near vârful pietrei (2192 metres). it flows as a rapid river from south to north until it reaches the village of bucova, where it changes direction and turns west. its first major tributary is the marga river; further down it collects the waters of the river rusca. before entering oțelu roșu, bistra collects its greatest influx of waters, the bistra mărului. near the town of caransebeș, it flows into the timiș. its length is and its basin size is .