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?