Willows are regarded by Native Americans as being relatives of the four winds, as the seeds are carried wildly by the wind in four directions. A secondary relation is to the water, as they're often found growing by streams. The spirit of the tree is thought of as versatile and mutable and, not surprisingly, the main way they used red willow bark in their life and ceremonies is in relation to air and water.
For example, Hopi and Navajo clans used willow to make prayer sticks and amulets, whilst others used the plant to make water carriers, arrow shafts or emblems of the four winds.
The bark works well in incense and was an important ingredient in sacred smoking ceremonies. It's calming and soothing, making it an ideal herb for use with clearing purposes and during quiet sessions of meditation.