The answer to the crossword question “Mountains where St. Bernards were originally bred” is ALPS. The Alps are a mountain range in Europe that spans across several countries including France, Switzerland, Italy, and Austria. St. Bernards, a breed of large dogs known for their rescue abilities, were originally bred by monks in the hospice of the Great St. Bernard Pass in the Western Alps. These dogs were trained to rescue travelers who were lost or trapped in the snowy mountains. Today, St. Bernards are still used for search and rescue operations in the Alps and other mountainous regions around the world.