Gap in the Grid by Matt Briggs AT COSTCO, WHILE WAITING FOR MY TIRES TO BE FIXED, I went for a walk along the Green River. I am at the Tukwila CostCo on a road named after the warehouses. I am in the parking lot of an office park of small businesses in warehouses. A stand of cotton-wood trees surrounds a pond that at first, I take to be an oxbow of the Green River, a slough of wet land.