The Karoo is the semi-desert area of South Africa. Gariep Dam lies within the Great Karoo, specifically in the Upper Karoo which has a higher elevation compared to the Lower Karoo, to the west. (The Little Karoo lies to the south, on the coastal side of the Swartberg Mountains.)

The Karoo was formed by sedimentation of an inland sea over the period 320 to 180 million years ago, and is rich in fossils. Thereafter, volcanic activity pushed magma through vertical cracks to form “dykes” and  horizontally in-between sedimentary layers which formed “sills”. The soft sedimentary rock weathered away except underneath the dolerite sills, which created the flat-topped and step-down profiles of the Karoo koppies.

The flora of the Upper Karoo is mainly dwarf schrubs and grass. Sparsely populated, the Karoo has dark skies which are ideal for stargazing.

Economic activity in the Karoo is mostly livestock farming (sheep, goats and cattle) and game farming. As in most of South Africa, San people were present in the Karoo, when large herds of springbok frolicked across the plains. Small numbers of springbok still move across Karoo farms.

A dolerite dyke. As the surrounding sediment weathers away, the dyke crumbles to a mound, which in this photo extends past the race’s start/finish venue and into the Gariep Dam. Both running routes pass just above the point from where this photo was taken.

Photo: Conrad van den Berg

Dolerite sills are visible in this Karoo koppie on the Venterstad–Burgersdorp road, 30km from the race venue.

Photo: Conrad van den Berg

Fossilised bones from animals that lived more than 180 million years ago are abundant in the Karoo. These fragments were collected beneath the koppies along which you will run.

Photo: Conrad van den Berg

San art, showing a hunter with bow and arrow, and an antelope. It is situated on one of the properties through which the running routes go but is not open to the public.

Photo: Conrad van den Berg


The Gariep Dam, fed by the Orange River, is the largest water storage reservoir in South Africa. It’s surface area is about 370 square kilometres when full. The dam wall is 88 metres high and 914 metres long at the top. A hydro-electric power station is situated to the side of the dam wall.

The Orange-Fish River Tunnel diverts a portion of the Orange River’s water from the Gariep Dam to the Great Fish River. At 82,5 kilometres, it is the fourth longest tunnel in the world.

The 50 metre high Hennie Steyn bridge, which crosses the Orange River at the inlet side of the dam, is over a kilometre long and the longest in South Africa.

The construction of the dam created the towns Gariep Dam, at the dam wall, and Oviston, at the tunnel’s water intake tower. Other towns around the dam are Norvalspont, Venterstad and Bethulie.


Google Earth image with towns, dam features and race routes

The Gariep Dam overflowing

 Photo: Carina van der Walt


The water intake tower of the Orange-Fish River Tunnel at Oviston
Photo: Juanita Vorster

The combination rail/road Hennie Steyn Bridge near Bethulie is a perfect place for watching the sun set over the Orange River where it flows into the Gariep Dam.

Photo: Carina van der Walt


Schalkwykskraal is home to Driekwartblou Guest House & Venue, the start and finish point for the race. Driekwartblou and the farmhouse are close to the water—a few hundred metres when the dam if full and about a kilometre when the dam level is low.

The farm is home to Merino sheep and Nguni cattle.

A barn and a shed are on occasion changed into function venues. Saturday morning’s registration and food serving take place in the barn.


Merino sheep graze on the higher-lying section of Schalkwykskraal.

Photo: Carina van der Walt

Nguni cattle

Photo: Carina van der Walt

The sheep-shearing barn is at times used for functions.

Photos: Carina van der Walt (left), Conrad van den Berg (right)


Gelykfontein has been in the Van der Walt family since 1884. Currently the 6th generation family farms with thoroughbred race horses, Nguni cattle, Ankole cattle, Rubicon Merino sheep, Meat Master sheep and indigenous veld goats. Gemsbok, kudu and eland are also kept. The aim is for a balanced farming operation in terms of veld utilisation, and careful selection of stock to ensure best quality genetics, hardiness and productivity. Gelykfontein was the first farm in this area of the Karoo to introduce Nguni cattle.

Morning Glory Cottages (self-catering and B&B) is situated on the farm.


Clockwise from top left: 1) Veld goats, 2) Gemsbok, 3) Ankole bull, with Nguni cows and calves, 4) Race horse from Gelykfontein at the National Yearlings Sales 2020
Photos: 1,2&3 van der Walt family, 4 Candiese Marnewick

Nguni cattle graze as the sun sets over Gelykfontein; Gariep Dam in the background

Photo: Marie Vermeulen Breedt

Gelykfontein owner Schalk van der Walt in front of the rock formations that runners will see when they pass through the kloof.

Photo: van der Walt family


Oviston Nature Reserve is managed by Eastern Cape Tourism & Parks Agency. It is stocked with a wide variety of antelope (eland, black wildebeest, gemsbok, red hartebeest etc.), ostrich and zebra. A large number of naturally occurring animals are present such as the smaller antelope (e.g. duiker, steenbok), hyena (brown), jackal, foxes (Cape and bat-eared), baboon, the smaller types of cat, and many other. The reserve is a birder’s paradise. A few of the many species are African fish eagle, steppe buzzard, black eagle, secretary bird, black korhaan, African spoonbill and blue crane.

Zebra and Red Hartebeest in Oviston Nature Reserve

Photo: Conrad van den Berg