Most people visit Denali National Park and Preserve during the short snow-free summer months, not realizing that the landscape of Denali is usually covered in snow for more than 8 months of the year. Denali's landscape spans from 62 to 64 degrees north latitud, where short winter days and a low sun angle help retain any snow that falls on the ground. There are places in the park, in the upper elevations of the Alaska Range (other than glaciers), that are snow covered year round.
The snowpack in mountainous terrain varies significantly from one area to the next. Topography, wind and aspect influence where the falling snow will accumulate. The Alaska Range itself acts as a barrier to the warm, moist weather systems moving from the south. Moist air carried from the Gulf of Alaska is lifted over the range, producing heavy precipitation on the windward slopes of the mountain range. Therefore, the south side of the park can have significantly greater snow depths than the continental interior where park headquarters is located. The annual snowfall at park headquarters is 81 inches, while the town of Talkeetna which lies south of Denali's border, receives 120 inches of snow annually.
Snow is a driving force in Denali's subarctic ecosystems. Snow depth and duration of snow cover affects a wide number of natural resource processes within Denali including wildlife population densities, herd movements, vegetation succession, soil temperature regimes, and hydrologic systems. Park scientists conduct snow surveys on a monthly basis from November through April at twelve locations throughout the park as part of a cooperative agreement with the Natural Resources Conservation Service (NRCS). Individuals, organizations, and state and Federal agencies use these data for decisions relating to agricultural production, fish and wildlife management, municipal and industrial water supply, urban development, flood control, recreation power generation, and water quality management.