[Marak]

Hmm, seems he has a habit of copying the art of others.

Check this out:

[TheSarce]

Here's a clearer pic of the same Churchill "Cheyennes" painting, this one's of a postcard in a set offered by a museum. Still haven't found the original, non-Churchill source image, though.

Found it here, Turtle Island Publishing, the caption reads:

Museum Collection Notecards
Institute of American Indian Arts
These high-quality blank notecards feature artwork from five renowned American Indian artists in the IAIA Museum Collection. Their work reflects the diverse tribal sensibilities that exist among native nations. T. C. Cannon (Caddo/Kiowa), Jonathan Warm Day (Taos Pueblo), Peggie Deam (Suquamish), Ward Churchill (Keetoowah/Cherokee), and Randy Chitto (Choctaw) are featured in this first volume.
Ten notecards, 2 each of 5 images. 5 ¼ x 4 ¼ ".
Suggested retail $7.95
ISBN 1-928816-12-6