Simplify the following text for a Grade 10 native English-speaking person.
Original: At the peninsulaâ s widest point , it is 430 km from the Bloomfield River , in the southeast , across to the west coast ( just south of the Aboriginal community of Kowanyama ) .
Simplified: At the peninsulaâ s widest point , it is 430 km from the Bloomfield River , on the east coast , to the Aboriginal community of Kowanyama on the west coast .