In August, my parents and I are riding from Detroit, Michigan to Hermosa Beach, California to visit my sister.  We figured this is the time to go since they are getting up in the years.  So far our route is looking to be whatever Garmin says its going to be.  On the way down we plan on going the northern route via I-80 and on the way back we'll do the southern route of I-40.  There's a huge expanse of territory in-between these two locations.  Does anyone have a detour that we just shouldn't miss?

If you have the time, go through south Dakota and see the sights.  The hills around sturgis are amazing rides.  Then, cut through Utah on the way and see Zion. When you get to California, experience mull holland drive and the rock store, Angeles crest highway and a night ride on Hollywood boulevard...all excellent
Howard

If your smart you will never go back to Detroit!!!!!

Where do you start on what to see and do?? Once you get to the CO, UT, NM, AZ and SoCal areas there is so much that it will take a whole summer and then some. Go to some tourism sites for the various areas and bone up on what floats your boat and stay off the slab for a more enjoyable trip.