Starting with a 1904 treaty, and followed by another in 1911, Maasai lands in Kenya were reduced by 60% when the British evicted them to make room for settler ranches, subsequently confining them to present-day Samburu, Laikipia, Kajiado and Narok districts. Maasai in Tanganyika (now mainland Tanzania) were displaced from the fertile lands between Mount Meru and Mount Kilimanjaro, and most of the fertile highlands near Ngorongoro in the 1940s. More land was taken to create wildlife reserves and national parks: Amboseli National Park, Nairobi National Park, Maasai Mara, Samburu National Reserve, Lake Nakuru National Park and Tsavo in Kenya; and Lake Manyara, Ngorongoro Conservation Area, Tarangire and Serengeti National Park in what is now Tanzania.