Are you able to get a National Parks Passport stamp here?

You can get a stamp at the Washington Monument visitors building for WWII and at the visitors center between the Lincoln snd Vietnam memorials

Not here you have to go to parkway headquarters at 700 George Washington Memorial Pkwy, McLean, VA 22101. All 31 parkway-related stamps are available at parkway headquarters on weekdays from 8 am to 4:15 pm. A selection of these stamps is also available at Arlington House, the Arlington National Cemetery Visitor Center, Clara Barton National Historic Site, Glen Echo Park, and Great Falls Park.

No