Labor Day weekend is upon us, and for many Coloradans, that means one thing: It’s time to start thinking about hitting the slopes. In addition to the big gear sales this weekend, registration is now open for Colorado Ski Country USA’s popular youth ski and snowboard passport programs, the trade association announced Friday. With the Colorado Ski Country USA Passport, fifth graders get three days of free skiing or snowboarding at each of 20 participating resorts.