Simplify the following text for a Grade 8 native English-speaking person.
Original: Fifty of the mountains exceed 4,000 m with the highest , Monte Rosa , reaching to 4638 m , and there are numerous glaciers including several of the largest in the Alps .
Simplified: Fifty of the mountains are more than 4,000 m high , with the highest , Monte Rosa , that reaches to 4,638 m ( 15,217 ft ) , and there are many glaciers .