I live in BC, Canada and have Class 5 driver license. I want to move to the USA (state Washington) in H1-B status and wondering how I can get US driver license. I heard that there is some kind of agreement between BC and Washington state and no exams or tests needed, so it is simple exchange. Is it true?
It is true. The State of Washington has similar agreements with British Columbia, Germany and Korea.
As long as your BC license is valid, you can follow the procedures same to the people holding an out-of-state US license. See here. This is only for British Columbia licenses, other Canadian licenses holders should take the test.