Snowmobile riders pause to hold a large American flag in a show of patriotism during this year’s High Flight Heroes ride in Island Park, held earlier this month. | Courtesy Ronnie Webber ISLAND PARK — Eight veterans and first responders from across the country gathered in Island Park in early March for an unforgettable backcountry snowmobiling experience designed to offer something organizers call “throttle therapy.” Participants, who were nomin…