It was not long before we passed the Dakota line, marked by a post and a pile of tin cans.  Shortly before noon Ollie made a discovery.

“What are those little animals?” he cried.  “Oh, I know—­prairie-dogs!”

There was a whole town of them right beside the road, with every dog sitting on top of the mound that marked his home, and uttering his shrill little bark, and marking each bark by a peculiar little jerk of his tail.

“How do you know they are prairie-dogs?” asked Jack.

“They had some of them in the park at home,” said Ollie.  “But last fall they all went down in their burrows for the winter, and in the spring they didn’t come up.  Folks said they must have frozen to death.”

“Nonsense,” said Jack.  “They got turned around somehow, and in the spring dug down instead of digging up.  They may come out in China yet if they have good-luck.”

“I can hardly swallow that,” replied Ollie.  “But, anyhow, these seem to be all right.”

There must have been three or four hundred of them, and not for a moment did one of them stop barking till Snoozer jumped out of the wagon and charged them, when, with one last bark, each one of them shot down his hole so quick that it was almost impossible to see him move.

“Now that’s just about the sort of game that Snoozer likes!” exclaimed Jack.  “If they were badgers, or even woodchucks, you couldn’t drive him at them.”

“I don’t think there is much danger of his getting any of them,” said Ollie.

We called Snoozer back, and soon one of the little animals cautiously put up his head, saw that the coast was clear, gave one bark, and all the rest came up, and the concert began as if nothing had happened.

“I suppose that was the mayor of the town that peeped up first?” said Ollie.  “Yes, or the chief of police,” answered Jack.  We camped that night by the bed of a dry creek, and watered the horses at a settler’s house half a mile away.

“That’s the most beautiful place for a stream I ever saw,” observed Jack.  “If a man had a creek and no bed for it to run in, he’d be awfully glad to get that.”

The next day was distinctly a prairie-dog day.  We passed dozens of their towns, and were seldom out of hearing of their peculiar chirp.

“I wonder,” said Ollie, “if the bark makes the tail go, or does the tail set off the bark.”

“Oh, neither,” returned Jack.  “They simply check off the barks with their tails.  There’s a National Prairie-Dog Barking Contest going on, and they are seeing who can yelp the most in a week.  They keep count with their tails.”

At the little town of Oelrichs we saw a number of Indians, since we were again near the reservation.  One little girl nine or ten years old must have been the daughter of an important personage, since she was dressed in most gorgeous clothes, all covered with beads and colored porcupine-quill-work.  And at last Ollie saw an Indian wearing feathers.  Three eagle feathers stuck straight up in his hair.  He was standing outside of a log house looking in the window.  By-and-by a young lady came to the door of the house, and as we were nearer than anybody else, she motioned us to come over.