Complex sentence: The site was renamed "America's Stonehenge" (a term coined in a news article in the early 1960s) in an effort to separate it from roadside oddity sites and reinforce the idea that it is an ancient archaeological site.
Split into simpler sentences: The site was renamed "America's Stonehenge" (a term coined in a news article in the early 1960s). It was an effort to separate it from roadside oddity sites and reinforce the idea that it is an ancient archaeological site.