Zip - what time of year are you doing your trip? The Going-to-the-sun road in Glacier usually doesn't even opun until the 1st of July - so better to time your plans accordingly. Going up thru Banff, Jasper on Icefields Parkway in early June we still encountered much snow and ice-covered lakes in 2008 - just something else to factor in! That said - like many others - we'll throw down some serious daily mileage thru areas we have already travelled, to maximize our time in new destinations. No matter what the speedometer reads, over the years we have figured out that our average speed is always pretty close to 50 mph. So - to cover 500 miles is 10 hours, etc. works for us. ST