The art installation "River of Air" is being created by California-based sculptor Ned Kahn. He is well-known for his large, wind-activated sculptural installations.
The material specifics of the "River of Air" were not explicitly detailed in the available information. Ned Kahn commonly utilizes elements such as wind, water, and light to create his kinetic artworks, which often involve reflective or translucent materials that interact dynamically with natural forces. For additional insight on similar works by Ned Kahn, you might visit Denver Public Art, where his installation "Field of Air" is featured.