Every year, when the grass of the Serengeti in Tanzania runs short, more than a million wildebeest, together with hundreds of thousands of zebra and gazelle, turn north toward the fresh pastures of Kenya. Between them and the green plains of the Maasai Mara flows the Mara River. It is narrow, brown and steep-banked, and full of crocodiles, and every animal must cross it. What happens at its edge is often called the greatest wildlife show on Earth.
The river crossings are the drama at the heart of the Great Migration, and understanding the river helps you plan a safari to see them.
The river
The Mara rises in the Mau Escarpment in Kenya and flows some four hundred kilometres south-west, through the Maasai Mara National Reserve and into Tanzania, where it crosses the northern Serengeti before emptying into Lake Victoria near Musoma. It is the only permanent river in the Mara ecosystem, so it provides water for wildlife year-round, and it holds large numbers of hippos and some of the biggest Nile crocodiles in Africa. Along its banks, riverine forest offers shade and cover for leopards.
The crossings
The migration is a circular movement that follows the rains. From around July, herds gather on the Serengeti side of the river and begin to cross north into the Mara. From about October, as the rains return to the south, they cross again in the opposite direction. Crossings depend on the rains, the state of the river and the mood of the herds: they can hesitate for days and then plunge all at once.
- July: first herds arrive; early crossings often at the Sand River and southern Mara.
- August and September: the peak. The largest herds are on the Kenyan side and crossings can happen daily.
- October: herds start to cross back to Tanzania, and activity shifts to northern Serengeti.
- November and December: herds move south again toward the short-grass plains.
The migration is rain-led, not calendar-led, so these are probabilities, not promises. A good guide reads the herds, the weather and the radio, and positions you before the crowd forms.
Where the crossings happen
On the Kenya side, popular crossing points include those near the Lookout Hill area, the Serena crossing, Cul-de-Sac, Paradise Plains and the Mara Triangle, where the sinister-sounding Mortuary crossing is well known for the number of animals lost. Kichwa Tembo, in the private conservancies to the north, is often quieter. On the Tanzania side, the northern Serengeti around Kogatende and the Lamai Wedge sees crossings into Kenya.
Further west, in the Serengeti’s western corridor, the herds cross the Grumeti River, usually between May and August, another dramatic but often less crowded scene. Between the two countries the Sand River, dry and treacherous with quicksand, sometimes becomes the main scene of the drama when the Mara River crossings are delayed.
What a crossing is like
You might wait for hours. Herds gather on the bank, milling, calling, and moving to the edge and away again. Then one animal jumps, and the rest follow in a wave, hooves striking the water, dust rising, crocodiles lunging, lions and hyenas waiting on the far bank. It may last minutes or much of a day. Some crossings are calm, and some are chaos. Every one is different.
Watching well
- Patience matters. Sitting quietly and watching is better than chasing.
- Keep your distance. Vehicles that crowd the bank can prevent herds from crossing. A good guide will hold back so the animals can move.
- Do not litter, stay in the vehicle and keep voices low.
- Choose the right camp. Being close to the river saves hours of driving. Some conservancies limit vehicle numbers, which gives a calmer experience.
- Accept nature’s terms. A safari cannot guarantee a crossing. Many travellers find that the days between crossings, with lions and cheetahs on the plains, are just as memorable.
Practical information
- Kenya side: the Maasai Mara is about five to six hours by road from Nairobi, or a 45-minute flight to airstrips. Our page on Maasai Mara National Reserve covers the reserve.
- Tanzania side: the northern Serengeti is reached by light aircraft or a long drive. See our page on Serengeti National Park.
- Crossing borders: the two sides are separate parks with different fees and rules. Check our Visa & Entry Requirements.
- Health: malaria is a risk; see our Health & Safety page.
The Mara River with Offmap Safaris
We plan migration safaris around the crossing seasons, often three to five nights in the Mara or northern Serengeti, and are honest about the odds. Plan your safari, message us on WhatsApp +256 701 243 304 or email [email protected]. Read our Responsible Travel page for guidance on wildlife viewing.