Climbing Kilimanjaro is less a mountaineering expedition than a walk through the world's ecosystems compressed into a vertical column. The montane forest that rings the base is dense, humid, and loud with birdlife: white-necked ravens patrol the canopy, and blue monkeys move through the understory. Higher, the forest thins into heather and moorland, where giant groundsels and lobelias grow in forms found nowhere else. Above 4,000 meters the vegetation drops away entirely, leaving an alpine desert of volcanic scree and thin air. And at the summit, Uhuru Peak, glaciers that have persisted for thousands of years cling to the crater rim, though they have retreated dramatically in recent decades. It is possible to begin a climb in sweltering tropical heat and summit in temperatures well below freezing, all within a few days.

German colonial authorities first declared Kilimanjaro and its forests a game reserve in the early twentieth century. In 1921, the British colonial administration redesignated it a forest reserve. The mountain above the tree line, roughly 2,700 meters, became a national park in 1973 under newly independent Tanzania. UNESCO recognized its global significance in 1987, and in 2005, the park expanded to include the entire montane forest belt, which had previously been managed as a separate forest reserve. This layered history of protection reflects how each governing power recognized, in its own way, that Kilimanjaro was not merely a landmark but an irreplaceable ecological system.

Despite the mountain's fame as a climbing destination, its forests harbor a rich wildlife community that most trekkers pass through too quickly to appreciate. Kilimanjaro tree hyraxes, small nocturnal mammals with an eerie shriek, inhabit the timberline zone alongside grey duikers and assorted rodents. Bushbucks and Abbott's duikers appear above the treeline in scattered locations. Cape buffalo browse the montane forest and occasionally wander into the moorland. Elephants move between the Namwai and Tarakia rivers and sometimes range to surprising elevations. In the forest itself, blue monkeys, eastern black-and-white colobus monkeys, bushbabies, and leopards all find habitat, though the leopard remains as elusive here as everywhere else in Africa.

Kilimanjaro draws roughly 50,000 to 60,000 climbers a year, making it one of the most visited high-altitude destinations on Earth. During the 2012-2013 budget year, the park recorded 58,460 tourists, of whom 54,584 were international visitors, and generated US$51 million in revenue, the second-highest of any Tanzanian national park. The park headquarters at Marangu, about 44 kilometers from the town of Moshi and 86 kilometers from Kilimanjaro International Airport, serves as the starting point for several trekking routes. Each route offers a different character, from the popular Marangu route with its hut accommodations to the more remote and scenic routes on the mountain's western and southern flanks. The economic impact ripples far beyond park fees: guides, porters, cooks, and equipment suppliers form an industry that sustains communities across the Kilimanjaro Region.

Kilimanjaro's glaciers have become one of the most visible symbols of climate change in Africa. The ice fields that have capped the summit for millennia have shrunk dramatically, and their continued retreat raises questions about the mountain's hydrology, its ecosystems, and its identity. The montane forests that ring the park depend on moisture systems linked to the mountain's elevation and ice cover. Named one of the Seven Natural Wonders of Africa in 2013, Kilimanjaro remains a place where the full sweep of the natural world, from equatorial forest to glacial ice, exists in a single vertical transect. How long all of those zones will coexist is the question that hangs over every step toward the summit.