Freedom 250, a nonprofit, has rolled out a fleet of six mobile museums known as “Freedom Trucks” that are traveling across the United States to celebrate the 250th anniversary of the signing of the Declaration of Independence. One of the trucks has been scheduled to camp out in Rainier at the boat ramp/boat launch parking lot Saturday through Tuesday, June 20-23, and will be open to the public from 10 a.m. to 5 p.m.Through the museum, visitors e…