We will be visiting Oregon in July. We are coming from Alberta, Canada and will be driving down the coast from Cannon Beach to Florence. We will be travelling in a 35ft Motorhome and towing our Van. Wondering which route would be the best to take home, meaning the least hills as we are driving the Motorhome. Should we take highway 5 from Eugene or should we keep going from Eugene to 97 up to 84. Are there any roads we should avoid on our trip?