Simplify the following text for a Grade 6 native English-speaking person.
Original: Elevations in the park range from about 6100 t. The terrain in much of the park is dominated by ridges and valleys running roughly north and south ; many of these ridges peak at an eastâ `` west crest near the park 's northern border which turns more northerlyâ `` southerly towards the park entrance .
Simplified: Elevations in the park range from about 6100 t. The terrain is dominated by ridges and valleys running roughly north and south .