Hi Michele,
As Paulett mentions, Chaco Canyon is a very famous site that has strong solar connections. You can find out more about it at www.traditionsofthesun.org.
Big Horn Medicine Wheel is another great example of a solar observatory. It is located in Wyoming. Visit http://solar-center.stanf....edu/AO/bighorn.html for more information about this site.
There are also lots of smaller sites that the indigeous people of North America used to observe the Sun. Unfortunately, many of these have been destroyed by building roads, cities, etc. and in many cases, the knowledge about these sites has been lost.
-Nancy