y the Beavers start a dam on some stream, right opposite a good
grove of poplars. When these are all cut down and the bark used for
food, the Beaver makes a second dam on the same stream, always with a
view to having deep water for safety, close by poplars for food. In this
way I found the Beavers at Yancey's in 1897 had constructed thirteen
dams in succession. But when I examined the ground again in 1912, the
dams were broken, the ponds all dry. Why? The answer is very simple. The
Beavers had used up all the food. Instead of the little aspen groves
there were now nothing but stumps, and the Beavers had moved elsewhere.

[Illustration: Beaver using his Tail as a Trowel]

Similarly in 1897 the largest Beaver pond in the Park was at Obsidian
Cliff. I should say the dam there was over four hundred yards long. But
now it is broken and the pond is drained. And the reason as before--the
Beavers used all the food and moved on. Of course the dam is soon broken
when the hardworking ones are not there in their eternal vigilance to
keep it tight.

There are many good Beaver ponds near Yancey's now and probably made by
the same colonies of Beavers as those I studied there.

Last September I found a fine lots of dams and dammers on the southeast
side of Yellowstone Lake where you may go on a camera hunt with
certainty of getting Beaver pictures. Yes, in broad daylight.

Let me correct here some popular errors about the Beaver:

It does not use its tail as a trowel.

It does not use big logs in building a dam.

It does not and cannot drive stakes.

It cannot throw a tree in any given way.

It finishes the lodge outside with sticks, not mud.

THE OTTER AND HIS SLIDE

[Illustration]

Every one of us that ever was a small boy and rejoiced in belly-bumping
down some icy hill, on a sled of glorious red, should have a brotherly
sympathy for the Otter.

While in a large sense this beautiful animal belongs to the Weasel
family, it has so far progressed that it is one of the merriest,
best-natured, unsanguinary creatures that ever caught their prey alive.
This may be largely owing to the fact that it has taken entirely to a
fish diet; for without any certain knowledge of the reason, we observe
that fisherfolk are gentler than hunterfolk, and the Otter among his
Weasel kin affords a good illustration of this.

We find the animals going through much the same stages as we do. First,
the struggle for food, then for mates, and