This is the original cover painting for the Volume #1 in the "White" trilogy by Norman Sharam,  published by Little, Brown, 1987.  Beautifully rendered in gouache and acrylic on illustration board in panoramic/wraparound format, c. 11.5" x 15.75"  - a very fine example of Pether's attention to detail in scenery and characters,  and  comes with a label attesting to its authenticity signed by Pether's widow, mounted to the back.