While Tonto digs a grave for the "half-breed" Collins, the Lone Ranger prepares Scout, their only horse, for travel. You might think Tonto would be the best person to deal with his own horse, but that would mean the Ranger's doing manual labor and getting his hands dirty. Gravedigging is for menial workers like Tonto, not for noble heroes like him.
"I’ve got to get a mount of some sort," the Ranger tells Tonto. "We’ll head off toward Wild Horse Valley." It's a remote place where the horses are "unknown and unmolested."
If you thought Tonto would ride his own horse while the Ranger walked, or the Ranger would ride behind Tonto, think again. Both walk because it wouldn't do for Tonto to seem better than his master. Riding Scout while the Ranger walked would make Tonto taller, more impressive-looking. Since the white man is inherently superior, that's unacceptable.
When they reach the valley, they see a buffalo about to gore a fallen white horse. The Ranger downs the buffalo with one shot. Although he cares about killing men, he apparently doesn't care about killing animals. A live horse is worth a dead buffalo.
They minister to the wounded horse, "tending his battle hurts, and caring as best as they can." Eventually the horse rises and we can see this wild stallion has horseshoes. Oops.
Tonto again demonstrates his product-branding skills when he describes the horse as "Like mountain with snow. Silver white." The Ranger decides to call him Silver.
A man and his horse
Despite being wild, the grateful Silver submits to the Ranger's touch. The Ranger readies him to ride, saying he'll use a hackamore (a rope around the muzzle) rather than a bridle for now. The two begin to work and learn together.
Then comes this remarkable bit of narration:
Proving the point, Tonto's next line is, "Me got everything packed." How ironic. While the Lone Ranger and Silver become bosom buddies, Tonto continues in his role as unhired help. Packing, fetching, and other menial chores apparently will be his lot in life.
As the Lone Ranger and Tonto ride off together, one more thing becomes clear. The Ranger is 2-3 inches taller than Tonto and Silver is 2-3 inches taller than Scout. No doubt the creators chose these height differences intentionally. They were still a few decades away from having a minority sidekick (Mr. T?) who was more physically impressive than the white hero.
For more on the subject, see The Lone Ranger.