Natural boundary of Uttar Pradesh

 

	North Mostly defined by the Shivalik range of the Himalayas, offering a natural demarcation from Nepal and Uttarakhand.
West Partly demarcated by the Yamuna River in certain segments, separating it from Haryana and Rajasthan. South-West – Chambal River		East Mainly marked by the Ghaghara and Gandak rivers, forming a natural border with Bihar. Karmnasha, Gandak and Ghaghra rivers divide the boundary of Bihar and Uttar Pradesh.
	South and Southeast The Bundelkhand Plateau, Vindhya Mountain Range and Baghelkhand Plateau serves as a partial natural boundary with Madhya Pradesh and Chhattisgarh.

 The Chambal River forms a natural boundary between UP and which state? - Madhya Pradesh (UPPCS 2020)

 Ghaghara and Gandak rivers form the eastern boundary of UP with which state? - Bihar (UPPCS 2022)

Source - Self Study Wala UPPCS Mains GS VI Book