You can have a veteran designation printed on your Washington driver licence or ID card as proof of your service. There is no fee if adding the designation is the only change you are making.
Apply online through Washington State Department of Licensing online services, or visit a driver licensing office.
A copy of your DD214 or equivalent, a next generation Uniformed Services ID card, a VA ID, or a letter from the Washington State Department of Veterans Affairs verifying your honorable discharge.