In a deep hole near the edge of the morass was a huge Hereford bull.  Most of the cattle in that country were Herefords.

The animal had without doubt become foundered in the swamp hole; but that was by no means the worst that had happened to him.  While held more than belly-deep in the sticky mud he had been attacked by the only kind of bear in all the Rockies that, unless under great provocation, attacks anything bigger than woodmice.

A big black bear had flung itself upon the back of the bellowing, struggling bull and was tearing and biting the poor creature’s head and neck—­actually eating the bull by piecemeal!

“Oh, horrors!” gasped Helen, sickened by the sight of the blood and the ferocity of the bear.  “Is that a dreadful grizzly?  How terrible!”

“It’s eating the poor bull alive!” Jennie cried.

Ruth had never ridden out from camp since Dakota Joe’s last appearance without carrying a light rifle in her saddle scabbard.  She rode a regular stockman’s saddle and liked the ease and comfort of it.

Now she seized her weapon and cocked It.

“That is not a grizzly, girls!” she exclaimed.  “The grizzly is ordinarily a tame animal beside this fellow.  The blackbear is the meat-eater—­and the man-killer, too.  I learned all about that in our first trip out here to the West.”

“Quick!  Do something for that poor steer!” begged Helen.  “Never mind lecturing about it.”

But Ruth had been wasting no time while she talked.  She first had to get her pony to stand She knew it was not gun-shy.  It was only the scent and sight of the bear that excited it.

Once the pony’s four feet were firmly set, the girl of the Red Mill, who was no bad shot, raised her rifle and sighted down the barrel at the little snarling eyes of Bruin behind his open, red jaws.  The bear crouched on the bull’s back and actually roared at the girls who had come to disturb him at his savage feast.

Ruth’s trigger-finger was firm.  It was an automatic rifle, and although it fired a small ball, the girl had drawn a good bead on the bear’s most vulnerable point—­the base of his wicked brain!  The several bullets poured into that spot, severing the vertebrae and almost, indeed, tearing the head from the brute’s shoulders!

“Oh, Ruth!  You’ve done for him!” cried Helen, with delight.

“But the poor bull!” murmured Jennie.  “See!  He can’t get out.  He’s done for.”

“I am afraid they are both done for,” returned Ruth.  “Take this gun, Jennie.  Let me see if I can rope the bull and help him out.”

She swung the puncher’s lariat she carried hung from her saddle-bow with much expertness.  She had practised lariat throwing on her previous trips to the West.  But although she was able to encircle the bull’s bleeding head with the noose of the rope, to drag the creature out of the morass was impossible.

He was sunk in the mire too deeply, and he was too far gone now to help himself.  The bear had rolled off the back of the bull and after a few faint struggles ceased to live.  But Bruin’s presence made it very difficult for the girls to force their ponies closer to the dying bull.