The new Arvada Walmart Supercenter hosts a Back to School Open House on Wednesday, August 9 from 10 a.m. to 11 a.m. Besides a number of displays highlighting trends in back-to-school merchandise and healthy lunchbox ideas, there will be FREE storewide samplings of food as well as vendors on site with giveaways. 9400 Ralston Rd., Arvada.