About the Region

The region covered is about 170 km in length and 6800 km2 in area; it is narrowest in the central part (near Iten) and widest in the north (where the Cherangany Hills project out to the west). The Cherangany is a system of old fold-mountains (the only one in Kenya) that, millions of years ago, became surrounded by vast lava flows from Mt. Elgon; flows which are now the rich agricultural soils of the Trans Nzoia and Uasin Gishu plains.
The eastern boundary of the region is the eastern edge of the Kerio Valley; in the south the Tugen Hills; in the north the Tiati-Masol Hills. The Tugen Hills are a narrow dome of rock that was uplifted from the middle of the Rift Valley floor. They have a poor, thin soil cover but are very scenic to cycle or drive across.

The most important geophysical fact about this region is the great altitude difference between the highlands and the lowlands. The highlands, mainly to the west and south, average 2400m in altitude, but rise to a maximum (in the Cherangany) of over 3500m. The lowlands (or valley), mainly to the east and north, average 1000m in altitude but drops to a minimum of about 800m (just south of the Masol Hills). The tremendous altitude difference creates tremendous differences in temperature, climate, vegetation, agriculture and life-style of the local people. Along the steep escarpments the differences are experienced as sharp changes in conditions within a short distance and a short time.
For visitors to the region the essential message is: In the highlands it can be very cold, especially at night, despite the equator being so close; and, in the lowlands it can be oppressively hot, even at night.