Broad Valleys Travel at the bottom of large valleys in usually safe. In periods of high hazard, an avalanche can run down into the valley, especially if there is an old slide path already established. These should be avoided unless you are confident that the slope is stable. In the Rockies it is east and north slopes that are usually the lee slopes. If you are standing under a cornice you are standing on a lee slope.
Cornices can collapse and trigger the slope below to avalanche.
On a ridge it is easy to walk out on to a cornice and initiate the collapse. This is a natural funnel for avalanches. Avoid gullies unless you are confident that it is safe. Traveling The safest routes are those that are not exposed to any avalanche hazard. When planning a trip and when touring, chose the safest reasonable lines available.