Mountain Pony by Henry Larom, 4th Scholastic paperback printing, T53, 1970, 245 pages. Cover by Leo Summers. Inside illustrations by Robert Frankenberg.
DESCRIPTION: “His first summer on Uncle Wes’ Wyoming ranch. city-bred Andy Marvin buys the frightened sorrel pony to stop Randy Garland from beating the pony. With cousin Sally’s help, Andy masters the mischevious Sunny. The tamed pony carries Andy through danger to round up some lost horses.
Together, boy and horse help Uncle Wes track down an unscrupulous band of game rustlers, and Sunny gets a reward from the governor.” (from the back cover)