Simplify the following text for a Grade 7 native English-speaking person.
Original: The Pamir argali ( also called Marco Polo sheep , for they were first described by that traveller ) may be more than 6 feet in length .
Simplified: It is also the biggest wild sheep , standing as high as 120 c and weighing as much as 180 k. The Pamir argali ( also called Marco Polo sheep , for they were first described by that traveller ) may attain more than 6 f in length .