Minecraft resource gathering/Snow
Snow occurs naturally in frozen biomes, and forms from snowfall in cold and frozen biomes. A shovel is required to collect snowballs, and Silk Touch is required for snow blocks. You can craft snow blocks using 4 snow balls.
Snow Golems produce snow wherever they walk, as long as they are in cold, frozen, or neutral biomes. If you are near a river, then you can build a Snow Golem inside an enclosed space, and continuously shovel the snow out from under the golem.