Admission to Vermont's state parks and historic sites isn't exorbitantly expensive, but if you're paying for a carfull of kids, it adds up — unless you're visiting during Vermont Days. The state doesn't charge visitors during one weekend each June; that Saturday, it's also free to fish without a license. The freebie is a welcome gift to penny-pinching parents. Two more: the Venture Vermont Outdoor Challenge and the Vermont History Trek. Complete these fun, self-guided scavenger hunts, and you and your family can earn free admission year-round. Download the entry forms at vtstateparks.com or vermontvacation.com. And read about our Venture Vermont and Vermont History Trek adventures this summer at kidsvt.com.