This may be of interest to you. It was a posting I recently did when someone had inquired on the routes between Vancouver and Banff. It is written the 'wrong way around' for you. It will compliment Soup's posting as I did not include the Kootenays.
I would make Banff a base for at least a day and take a trip up at least as far as the Columbia Icefields.
Most direct route, 847km, is Hwy1 to Hope, Hwy 5 to Kamloops and then Hwy 1 all the way to Banff. Vancouver to Hope is on 4 lane freeway, Vancouver suburbs, then rolling farmland past communities of Surrey, Langley, Abbotsford, with views of Mt Baker, 10550' volcano right ahead of you. To your right will be views of rugged Coast Mountains. At Abbotsford, land becomes flat and the road turns and enters narrower part of Fraser Valley with Coast Mountains to your left & Cascade Mountains to your right. Just before Chilliwack you will have Fraser River off to your left. Very scenic lakes near Chilliwack & lots of camping. Valley getting narrower with Harrison Hot Springs a few miles to your left and Bridal Falls almost right on the highway to your right. Pass right beneath the summit of Mt. Cheam. Road is now slightly undulating with Fraser River very visible to your right. At Hope, take Hwy 5, the Coquihalla, and now you begin to climb, up through the canyons where the first Rambo movie was filmed. Impressive mountains near summit. Begin long descent into Merrit, and you'll notice the trees getting smaller & the land drying out as you enter the grasslands. At Merrit you can stay on HWY 5 and go back up into the mountains again or take the two lane Hwy 5A, (six miles longer) past some very pretty lakes, and historic settlements. Either way, there will bea big descent into Kamloops to rejoin Hwy 1. After Kamloops, which is very dry and hot in the summer, You take Hwy One all the way to Banff. A first alternative to this route is to take Hwy 3 at Hope and head for Osoyoos at the southern end of the Okanagan Valley. This route is mainly two, some four lanes, goes up & down a bit and is a bit twisty between the summit (Manning Park) and Princeton, but is very scenic all the way. At Osoyoos, pronounced 'Oh soy eus', take Hwy 97 North up through the pretty but busy Okanagan Valley, with its bustling towns, vineyards orchards and resorts, passing by several lakes including the 75 mile long Okanagan Lake.You join Hwy one again at Sicamous. This route is about 100 miles longer. A second alternative is to leave Vancouver to the north on Hwy 99 up through Whistler. This is about 50 miles longer than the direct route, but is very scenic. At first you drive along Howe Sound, which is actually a Fjord, but no one uses that term here. Before you get to Squamish there is the huge rock mountain 'The Chief' and the beautiful Shannon Falls. After leaving Squamish, look off to your left for the stunning Tantalus Mountain Range. There are all kinds of spectacular places around this area, but I am not familiar how to get to them. Whistler has all kinds of activities year round, or you could just take a walk around the village or go into one of the big fancy hotels for a drink or a meal. Past Whistler and Pemberton, the road becomes 'interesting'! I have never taken my RV through here, but didn't notice anything too wild when I drove the car. The last route, Hwy 1 all the way, is about 40 miles longer than the direct route and goes up through the Fraser & Thompson Canyons, is a mix of 2 & 4 lanes. Passes by Hell's Gate, where you can take a cable car across the wildest part of the River. At Lytton you can see the very strange sight of the muddy Fraser & blue Thompson Rivers merging. This place is often Canada's hot spot with frequent 100+ temps. Ashcroft further along is BC's driest spot with a desert like 8" of rain per year. Sorry to give you so many choices, good job I never mentioned all the alternate routes through the Kootenays! ;)
