The Lyle post office will issue a special commemorative postmark on Saturday, Oct. 29, to honor the Lewis and Clark encampment at the mouth of the Klickitat River at Lyle -- 200 years ago to the day.

The unique postmark is free, and will be available at the "Lewis and Clark Station," a temporary post office that will operate under the awning on the sidewalk in front of the Lyle Hotel.