Sleeping Bear Dunes National Lakeshore, on the northeast shore of Lake Michigan, has become a haven for families that want to stretch their legs and get some fresh air as a break from hunkering down. Though the place isn’t as busy as it would be in a typical spring, “We’re seeing lots of traffic and people out and about in the park,” says Merrith Baughman, a park ranger and the chief of interpretation and visitor services. Park staff and law enforcement officials have been steering visitors away from barricaded trails…