From the Wikipedia page 
Tarime District is one of the seven districts of the Mara Region of Tanzania, East Africa. It was previously known as the "North Mara District". Its administrative seat is Tarime town. It is bordered from the north to east by the Kenyan districts of Migori, Trans Mara and Kisii, and to the east by the Maasai Mara game reserve. To the south it is bordered across the Mara River by the Serengeti and Butiama districts, and to the west by Rorya District.