Ice fields are made when it snows over many kilometers where the temperature is always way below freezing. Over hundreds of years the ice field is very heavy and big. Some ice fields are as large as the state of Texas.

An ice field is not really part of a glacier, but they do "feed" glaciers ice. Some ice fields like the Columbia Icefield is 325 square kilometers in size and it "feeds" ice to 8 different glaciers in the Arctic Circle. Water that melts from an ice field provides fresh water to the people who live near it.