Speaking of ice cream, we had some great stuff at Cascadian Farms in Rockport, on Hwy 20. They were wide waffle cones, and we bought some raspberries to put on top of the ice cream. Excellent stuff.
If you are in Washington later in July, the wild blackberries may be ripe, especially at the lower elevations. Bring leather gloves, ziplock bags, and long sleeves. Major thorns. But incredibly delicious -- the fresh picked stuff tastes nothing like store-bought berries.
In late August, the wild huckleberries and mountain blueberries are ripe, but I think that is beyond your time frame.
