The Botterkloof pass is a fairly substantial altitude gaining pass in the Northern Cape between Clanwilliam and Calvinia. It is the third of a trio of passes on the R364 route for those travelling from west to east. In rainy weather or snowy conditions, this pass can become very tricky; even in a 4WD vehicle. The pass descends a total of 345m over a distance of 11,3 km producing an average gradient of 1:33 with the steepest parts measuring in at 1:10. There are sections near the summit with near vertical, unguarded drop-offs, which can be a bit intimidating for drivers unaccustomed to feeling so exposed. The more dramatic part of the pass is in the first 2,5 km near the summit.
The origins of the name are probably due to the large number of Botterbome that grow in the kloof. Tylecodon paniculatus can reach heights of 2 m, making it the largest of the tylecodons. It is summer deciduous. The plants conserve energy by photosynthesising through their greenish stems during the hot dry summer months. The yellowish-green, papery bark is a very attractive feature of this plant and has given rise to the common name. During the winter, plants are covered with long, obovate, succulent leaves clustered around the apex of the growing tip.The botterboom is poisonous to stock, causing 'krimpsiekte'. In the past, the smooth, slippery stems were sometimes used to slide or ski at great speed down smooth rock faces or dam walls, adrenaline rushes before the days of bungy jumping!