This is a free sample pack for the AoA Canyons And Cliffs asset pack.
The sample pack contains a selection of mesas and buttes, as well as a selection of the larger cliff assets and waterfalls. This is a small part of the overall asset pack.
The full asset pack can be purchased here.
Most assets are provided in both custom colors and sample color versions.
Whilst these Assets are stored as png files in a folder structure suitable for use in Wonderdraft they would also be perfectly usable in most other graphics software.