It straddles the boundary between Nyandarua, Nyeri and Muranga counties. It covers the highest areas of the Aberdare Mountains in central Kenya and the Aberdare Salient to its east. Rhino Arca is a charity dedicated to protecting this critical habitat area. It extends over a wide variety of terrain, since it covers heights ranging from 2,100 to 4,300 meters above sea level. The Aberdare Mountains is a 160 kilometer long mountain range in the highlands about 100 kilometers north of Nairobi, with an average elevation of 3,350 metres. They are heavily covered with forest. Much of the range has been protected since its creation in 1950. The range attracts large numbers of walkers and climbers, operating from the main centers of Naivasha and Gilgil. The lower slopes have farms, while the higher areas are known for their wildlife. Oldoinyo la Satima (the mountain of the young bull) with 4,001 meters above sea level is the highest peak of the Aberdare mountains. As a curiosity, Queen Elizabeth became Queen of the United Kingdom while here on vacation.