Simplify the following text for a Grade 6 native English-speaking person.
Original: Lake Turkana ( or \/ tÉ rË kÃ nÉ \/ ) , formerly known as Lake Rudolf , is a lake in the Great Rift Valley in Kenya , with its far northern end crossing into Ethiopia .
Simplified: Lake Turkana , formerly known as Lake Rudolf , is a lake in the Great Rift Valley in Kenya . Its far northern end crosses into Ethiopia .