I'm going on a trip to Yellowstone NP in Jan. I need some good winter boots. I wear an 11 1/2 W Men's. Merrell and Keen my most recent non winter boots. Been happy with both. Would like something that is also waterproof. I've never snowshoed before so I have not idea what I should look for. What do you recommend? Preferably something in stock at the Washington DC or Bailey's Crossroads VA stores. I like to try on boots before buying. Thanks.