If you don’t have time to stop in at the Gateway Arch, you can still pick up a souvenir at the entrance.  The Arch Store To Go retail store sells a selection of the most popular items from The Arch Store, including t-shirts; mugs, cups and water bottles; ornaments; children’s books; and small Arch replicas and collectibles. Arch Store To Go is open weekends in May, and starting Memorial Day, it’s open every day from 9 a.m. to 5 p.m.  Of course, you can shop any time from the park’s online store.