wow thanks for the responses. I don't think we are going to do the go-down-south way because it seems to add quite a bit of distance and mileage to the trip, probably going to go up and back relatively the same route, just stopping at different places along the way and going through Canada back.
As for DUI in Canada, we are fairly responsible and I don't think any of us would ever drink and drive, not trying to get in any legal trouble, nothing ruins a trip worse. As for recreational pot in Colorado, I should have known the age was 21, silly me, this changes things a bit, since only half our group would be legal age, and i assume the laws are similar to underage drinking and furnishing alcohol for minors, like i said: NOT trying to get in any legal trouble, especially all the way out in Colorado, and especially not for something as dumb as pot; i guess me and my friend will just have to go without, and be especially careful that none of us could be accused of DUI, fine by me i'm not too into it anyway. I also assume the cops in Utah are looking out for people who bought legal weed in Colorado and bring it to Utah, so ill have to make sure we all know how important it is to keep it all in Colorado. Also i know that since we are going to be a car full of college kids, we are more likely to be pulled over than most other cars on the road, and then more likely to be searched as well. We will be sure to keep it under the speed limit (or at least really really close) and not carry anything illegal with us.
My brother and I have wanted to do this trip for a very long time and put a lot of planning and consideration into it so far. Everyone has very similar expectations and goals, our largest being to explore, camp, and hike in Zion National Park (My brother and I have been there twice, but due to our unadventurous parents, experienced it only through the car window, and through short walks we took while our parent's waited for us at the car; thus giving me a super strong urge to go back and explore the american southwest on my own trips). I'm doing most of the planning, as it's kind of my trip, but my brother and the friends who are coming with us, are very much in the loop, avid hikers/campers and well traveled, all comfortable sharing vehicle tent and hotel rooms for the whole trip, and iv'e been communicating with them quite a bit about it.
That aside, thanks for the advice. More about the attractions along the route would be sweet.