This book is an outstanding true account of a trip made by Zane Grey and a plainsman, Buffalo Jones--one of the last. Jones was a famous sportsman in North America at the turn of the 20th century and Grey a famous author of adventure stories. Unlike many of Grey's fictional novels of the old west, this is an account of a trip made to the North Rim of the Grand Canyon about 1908, for the purpose of tracking and capturing mountain lions. In those days, the North Rim was famous for the number and size of cougars--one mentioned in the book was 10' long, tip of tail to nape of neck, and weighed 300 pounds. The story is riveting with many details of the Arizona high desert and Grand Canyon areas of that era and gives a wonderful account of the Ponderosa Pine forest now known as the Kaibab National Forest.