Road trip Seattle to Grand Canyon via Montana
 

We are planning a trip from Seattle to Whitefish, MT and then southward to Yellowstone, Salt Lake City, Bryce Canyon, Painted Desert, Grand Canyon and flying back to NY from Phoenix. We have allowed 25 days (visiting in Seattle for about 7 days). We have never done anything like this. Any experienced traveler want to give us advice? Is it possible at a leisurely pace?

Am planning a similar trip (first time) in 1998...planning is probably more fun than doing it....am interested in responses.