Like Mount Nyiru to the north and the Mathews Range to the south, the Ndoto Mountains consist of Precambrian crystalline basement rock, mostly extremely durable gneisses and granites.

[1] The climate is semi-arid at lower elevations.

At higher elevations there are areas of higher rainfall, humidity, and cloud cover which support montane forests.

[1][2] The Ndotos Range Forest Reserve was established in 1956, and covers an area of 932.05 km2.

[3] The reserve contains about 101.55 km2 of dense forest.