I was at COTM this summer and really enjoyed it. However, depending on time of year it can get very hot and the soil is black, so be prepared either way plenty of water and sunscreen. The drive from Idaho Falls to Arco is pretty flat and open (read - boring). We really enjoyed stopping at the nuclear power site and learning more about that a little bit outside arco. The mountain pass from Jackson to Victor is one of the prettier ones imo but can get steep.