The contagious delta variant is driving up COVID-19 hospitalizations in the Mountain West and fueling disruptive outbreaks in the North. It’s a worrisome sign of what could be ahead this winter in the U.S. Meanwhile, trends are improving in Florida, Texas and other Southern states that bore the worst of the summer surge. But it’s clear that delta isn’t done with the United States. COVID-19 is moving north and west for the winter as people head indoors, close their windows and breathe stagnant air. A Vermont college recently suspended social gatherings after a spike in cases tied to Halloween parties. Hospitals in New Mexico and Colorado are overwhelmed.