What is the best route to Chelan?
As you can imagine this depends where you are coming from. Many folks are from the Seattle area or come in to Seattle/Tacoma Airport. The best choice from there is to come over Snoqualamie Pass on US 90, and then over Blewett Pass on SR 97.
If you are coming from areas North of Seattle, Stevens Pass on US 2 is your best option.
If you want a scenic route, then by all means travel the Methow Valley and Hwy 20 for one leg or your journey. Routes and options can be researched at www.CascadeLoop.com.