Complex sentence: On this ridge and also northward of the northern brook the land rises to rather over 200 ft. above the Ordnance datum and from the ridge it falls about 100 ft. to the southern brook and about 70 ft. to the northern.
Split into simpler sentences: On this ridge and also north of the northern brook the land rises to over. Above the Ordnance datum and from the ridge it falls about to the southern brook and about to the northern.