Complex sentence: Near the crest of the Fairweather Mountains, sits the Lituya and the North Crillon glaciers that are each about 12 miles long and one mile wide, with an elevation of 4000 ft (1,220m).
Split into simpler sentences: Near the crest of the Fairweather Mountains sit the Lituya and the North Crillon glaciers. They are each about 12 miles long and one mile wide with an elevation of 4000 ft (1,220m).