Henry V. Larom (1903–1975)

From vintage scholastic cover:

Andy heard the announcer bawl out the next event: "Red Wilson coming out of Chute Number Two!"
The Sway-backed gelding felt the sharp prick of spurs for the first time in his life and unwound like a spring. Brownie's first jump sent a surprised Red forward over the saddle horn. The second one loosened him up. The third sent him flying.
Red's voice when he stood up was hard. "You made a fool of me, Andy Marvin. I won't forget it. If things start to happen to you, don't say I didn't warn you.
That was the night Brownie disappeared.… (altro)

From vintage scholastic cover: Andy Marvin tames a tough little bronc and rips into action against the rustlers....His first summer on Uncle Wes' Wyoming ranch, city-bred Andy Marvel buys the frightened sorrel pony to stop Randy Garland from beating the pony. With cousin Sally's help, Andy masters the mischievous 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 gang of game rustlers, and Sunny gets a reward from the governor. ---- From the flyleaf: "Henry Larom was head dude wrangler for years on Wyoming's famous Valley Ranch. 'Some of the horses mentioned in this book are still out there and smart enough to sue me," he says.… (altro)