Warming weather in the region is an unmistakable clue that the winter recreation season is nearly over in Yellowstone National Park and on the John D. Rockefeller Jr. Memorial Parkway. The Grassy Lake Road will close on Thursday to over snow travel; and Yellowstone Spokesman Al Nash says so will the South and West Entrances to Yellowstone National Park. Once the last of the entrances used for winter travel is closed, Nash says it will be a number of weeks before they are reopened to wheeled vehicles. The West Entrance will be the first of them to reopen, but the other openings will come later since Nash says the roads in those parts of the park require more extensive work to clear. One of those consideredamong the most labor intensive to clear is the South Entrance road through Lewis River Canyon. Others that require extensive work are Craig Pass, Sylvan Pass and Dunraven Pass.