There are many fallacies or misconceptions about snow and its importance in the environment. One good example of this is found in the Rio Grande Basin in the Southwestern United States and Mexico. The Rio Grande, the third longest river in the United States, is sustained by snow accumulation and melt in the mountain rim regions which provide a major contribution to the total streamflow, despite flowing right through the heart of North America’s largest desert (Chihuahuan). Because the majority of the population in the basin resides in a few large cities in the Rio Grande Valley, which are all located in the desert there is little realization on the part of the urban residents that snowmelt is an important factor in their lives. This is true around the globe. Where agricultural water use predominates, however, the importance of snow for the water supply and food production is more widely known, although to a markedly smaller proportion of the population.