DDSF is a small patch of 42.27km situated along the hill chains running across the eastern part of Tumkur district.This range marks the boundary between the Krishna and Cauvery river basins.
The chains,starting with Kamandurga(1078m) and Nidugal(1062) in Pavagada Taluk,continues through Midigeshidurga(1141m) and other hillocks embracing some prominenet peaks like Madhugiridurga(1200m) Chennarajadurga(1141m), Koratagere(886m), Devarayanadurga(940m). It is part of the range running westward towards Banglore district, represented by Shivaganga and Savanadurga. Devarayandurga is the tallest hill range.
Devarayanadurga has an undulating terrain sloping steeply towards east and west, between Urdigere and Tumkur. It is the place of origin of small stream and tributaries.Principal one being,"Jayamangali", which rises in a gorge called "Jaladha gundi" and then flows towards north . A small brook called "Garudachala", takes origin in the south eastern portion of Devarayanadurga and flows towards north and join "Jayamangali" near "Holavanahalli". Shimsha a tributary of Cauvery is another major strean which originates in the southern part of Devarayanadurga and flows south-west and joins "cauvery".
Temperature: Max. Min.
During summer it may rise upto 36c.
Rain fall: Rainy season June to September.
Average rainfall 80-85 cm