MILK RIVER, Alta.—Nearly two years of being caged in Canada during the COVID−19 pandemic has some snowbirds anxiously waiting in their motorhomes and trailers in southern Alberta. The Eight Flags Campground in the small windswept town of Milk River, 18 kilometres from the Canada−United States border crossing at Coutts, is full of shiny, large RVs. It’s in anticipation of land and sea border crossings reopening Monday for fully vaccinated Canadians. Such crossings were closed to non−essential travel at the beginning of the pandemic in March 2020. “All of a sudden someone said the border’s opening and it just went nuts here,” said Helen Runka, who operates the campground. “They said they’ve been waiting to go back to the U.S. for two years and they’re not going to miss out.” The campground, which has 35 sites, has twice the number of bookings for this weekend. Some overflowparking is being offered near …