A quite legendary timeline about more developed Bronze Age Native American culture, created by Doug Muir in the earlier 2000s. It was one of the first online alternate history works/projects of its kind.
Since about 2010, the original website of the timeline has gone defunct. However, an archived version of the site is still accessible here, via the Wayback Machine of archive.org.
Giving Doug Muir's "Bronze Age New World" another look - A discussion from 2009, back when the original site still existed.
Bronze Age New World Alaska and Bronze Age New World: Empire of the Steppe were two other related projects, both of them created by ChugachMtnBlues. However, unlike Hnau's reimagining, they were set in Muir's original timeline and tried to follow its outline closely. You can think of them as an Alaskan spinoff and a Siberian spinoff of the original timeline.