Also North of Vegas is "the valley of fire" great place, but take water with you, lots of it. Zion the end of August is still very hot, but the nights and mornings are cool. nice drive is to do Zion, go through the tunnel to the east side, drive over to hwy 89, then go north. That is the lower portion of what is called long valley. Past the turn off to Alton Utah, there is another Hwy that goes over Cedar Mt. The sign will say Cedar city. Take that and you will be treated to one of the best scenic drives in North america. Near Duck Creek there is the ice caves. Stop and go through them. Further on is Navajo Lake. Good spot for renting a boat and just chilling on the lake. The meadows will no longer have flowers, but you will see all sorts of wild life. Cedar Breaks is on that same hwy. It is a miniture version of Bryce Canyon. Next major stop is for the Zion Canyon overlook. That is also if you follow along the rim back to where the trees are next to the road on the east side of the overlook, will be hidden off in those trees, a bristlecone pine forest with some trees being among the oldest on earth. After the overlook, you will head down some what was once rough canyon road following along the coal creek. Many opportunities for pictures along here. Finally at the end you enter Cedar City Utah, iwth one of the best award winning sheakspearn festivals in the world. They have many tickets they reserve fro preformance day, so getting a seat would not be hard. to finish the loop and take you back to Vegas, you are right at I-15 which is the road you will have taken to get to Utah and Zion. The trip over the mountain will be cooler temps as well.