Geographically, the province was a triangular tract of country of which the Indus River and its tributary the Sutlej formed the two sides up to their confluence, the base of the triangle in the north being the Lower Himalayan Range between those two rivers. Moreover, the province as constituted under British rule also included a large tract outside these boundaries. Along the northern border, Himalayan ranges divided it from Kashmir and Tibet. On the west it was separated from the North-West Frontier Province by the Indus, until it reached the border of Dera Ghazi Khan District, which was divided from Baluchistan by the Sulaiman Range. To the south lay Sindh and Rajputana, while on the east the rivers Jumna and Tons separated it from the United Provinces. In total Punjab had an area of approximately 357 000 km square about the same size as modern day Germany, being one of the largest provinces of the British Raj.