Complex sentence: Well-preserved Native American archaeological sites are a rarity in the Lake Erie plain and the amount of information found at the Sommerheim Park sites makes them one of the leading archaeological sites in the Erie area and the southern shoreline of Lake Erie.
Split into simpler sentences: Well-preserved Native American archaeological sites are a rarity in the Lake Erie plain. The amount of information found at the Sommerheim Park sites makes them one of the leading archaeological sites in the Erie area and the southern shoreline of Lake Erie.