IMHO: You should learn about avalanches before climbing or traveling in the back country where any avalanche possibility might exist. If you don't know whether or not the avy conditions are safe you should learn what you need to know to make those calls on your own. This means you are continually assessing the snow pack as you travel. You know what slope degree is most likely to be dangerous. You know the snow pack and previous weather events etc. The ranger might be right, but I sure wouldn't put my life in their hands. Take an Avy class, read the books, buy the gear, don't go alone. Avalanche and snow pack knowledge is scary. It seems like the more you know you realize the more you need to know.
Mike