It has the largest surface area of any extinct Volcano in the world (50km by 80km) and rises 3,070 metres (10,070 ft) above the surrounding plains. Its cooler heights offer respite for humans from the hot plains below, and its higher altitudes provide a refuge for flora and fauna.
The Peaks and the Caldera
Mount Elgon’s highest peaks are formed by high points around a jagged rim enclosing one of the world’s largest calderas, at 40km long and 8km wide. The tallest peak is the 4,321m Wagagi, followed by Sudek (4,303m), Koitobos (4,222m), Mubiyi (4,210m) and Masaaba (4,161 metres).
The Caldera was formed as a result of magma being drained from the chamber. When it could no longer support the overlying volcanic cone, it collapsed into a depression-like shape.
In the eastern corner of the caldera, hot springs are found at the start of the deep Suam Gorge. In the northwest, Simu Gorge was formed by the sheer weight of the water in the caldera cutting two stream beds out of the weak volcanic ash and agglomerate walls.
Its Wagagai peak standing at 4321 is the second highest in Uganda – after Margerita Peak of Rwenzori Mountain in western Uganda.
The mountain also contains one of the world’s largest calderas –a collapsed crater covering over 40kms – sitting at the top of the mountain. It also has many waterfalls on its slopes and hot springs that one can soak in.
It’s Flora and Fauna is beautiful and as you ascend the mountain slopes. You pass through dense montane forest and mixed bamboo belts. You then enter fascinating heath and moorland zones containing several interesting endemic plant species such as giant lobelia and groundsels.
Mount Elgon’s slopes are riddled with caves left by moving lava and erosion of soft volcanic deposits. The most accessible are Kapkwai Cave, near the Forest Exploration Centre, and Khaukha Cave on Wanaale Ridge. Historically, such features acted as shelters for locals and their livestock; later on they provided manure in the form of bat droppings. More recently, they were used by climbers and their porters, and even today, campsites are still located at Hunters Cave, Siyo Cave (near the hot springs), Mude Cave and Tutum Cave – ideal for overnight expeditions.
At the mountain top, you can easily spot primates such as the Black and White Colobus Monkey, Blue Monkey, and a variety of fascinating bird species, including Golden Winged and Tacazze sunbirds, Ross’s and Hartlaubs Turacos, Black and White Casqued and Crowned Hornbills, the endangered Lammergeier and the Jackson’s Francolin which is found nowhere else in Uganda. There are also buffalo, hyenas and leopards.
Mt. Elgon’s vegetation is banded into broad zones whose characteristics are dictated by altitude and rainfall. The lower mountain slopes are covered with dense forest and regenerating forests, hung with vine-like lianas, epiphytes and lichens.
The floor is covered with a carpet of ferns, orchids and flowering plants. Common tree species encountered in the tropical montane forest (1,500-2,500m asl) are olive Oleahochstetteri, prunus africanas, Elgon teak, podocarpus, cedar, Cordia, Neoboutania, allophyllus tombea and Aningueriaadolfi-friedericii.
The zone changes to mixed bamboo (malea) at 2,500-3,000m. The bamboo merges into open woodland dominated by hagenia abyssinica and African rosewood interspersed with hypericum – a giant form of St. John’s wort.
The heath zone (3,000-,3500m) is characterized by giant heather interspersed with grassy swards of blonde tussock grass dotted with pink and white everlasting flowers (ericriceum brownie and jonstonii), flame-colored gladioli, blue delphiniums and red hot pokers.
The moorland or Afro-alpine zone (3,500-4,321m) contains senecio elgonensis, Erica tree, giant lobelias with hairy leaves and plumes of tiny blue flowers, ladies’ mantle tussocks (archimilla elgonesis) and pink and white everlasting flowers.
The summit of the mountain is vegetated by rare Afro-montane species that include giant forms of lobelia and groundsel.