John Neihardt spent a summer at Big Spearfish Falls (pictured above) and met a dog-named Shep.
Suddenly, there he was beside me, wiggling abject apology for intruding. I recognized him at once.

Although we had never met socially, we had occasionally exchanged pleasantries, as one dog to another, on our goings and comings about the canyon. "Well, well," I exclaimed, "and look who’s here!" Apparently, he misunderstood my dialect at first, for he groveled before me with a guilty baring of the upper teeth. So I petted him on the head and said, "That’s all right, Shep, old man! You may come along and help me fish." Immediately he was another dog entirely. Intoxicated with joy, he raced wildly about me, around and around, as though pursuing a demented rabbit, yelping with enthusiasm the while.

When at length the spasm of delight was spent and I stopped to pet him, he placed his paws on my shoulders and licked my face. "I’m your dog forever and ever," he said

And I said, "No, you aren’t; you belong to a man up the canyon." And he said, "No, I am your dog forever because I love you."
And I said, "Oh well, if it’s like that, why of course---." And I began whipping the fast water for a strike while he sat upon his fluffy rump, observing me with tongueful curiosity.

I must have been casting with a nervous and especially inexpert hand that morning and a split second to soon. At any rate, I threw a gorgeous unhooked rainbow out upon the bank. It looked as though I were about to lose the prettiest fish I had ever seen for some time, for it was making back furiously toward the water with flapping leaps and bounds. It was almost there when Shep, seizing the opportunity for a bit of exciting fun, leaped upon the fish, tossed it into the air with his snout, and came down upon it with both front feet, thus blocking escape. So I got my fish.

There was no apologetic behavior from Shep after that. Evidently convinced by praise and petting that he had somehow done a worthy deed for his man, he took on the air of a prosperous partner. While I was casting, he would pace briskly up and down the bank, whimpering with anxiety and eager for action. If a hooked fish broke water in a burst of spinning glory, he would share in the excitement, barking wildly.

It soon became clear that Shep meant to keep me for his man, following me about all day and spending the night on my doorstep. If I tried to shoo him away, he flattened out his belly and looked utterly forlorn. When I finally took him to his owner up the canyon, he bolted, making for the brush with a snaky lowering of his head and desperate drooping of his tail. He did not turn up again until late that night, when I heard him whining at my back door. He slept that night beside my bed--- and many nights thereafter, for by gentlemen’s agreement he became my dog for the summer.

Several times during the summer, I made the trip by rail to Deadwood, spending the night in town and returning the next forenoon. Once after the train, with me in it, was well underway up the canyon, he managed to break loose and took out after the loud-mouthed monster that had stolen his man. Next day he celebrated the miracle of my return with old ecstatic orgy of delight. But it was clear thereafter that he wanted no truck with the foul beast. Whenever it invaded our private world, he gave it a savagely frank and thoroughly comprehensive barking over.

It was in the mournful waning of August 1907 that I saw Shep for the last time. Or did I?

It must have been a week or more after I reached my home in Nebraska that, the letter came. It was all about Shep, and he was dead. Refusing to remain with his friend Bobbie, he had saw himself to watch the front door of the vacant cabin facing the railroad. Twice a day, when the hated little train came through, there was the same savage assault on the monster. Then at last the iron beast had won, and Shep was caught under the engine drive wheels. It happened right there at the front door of the desolate cabin.

For sixty years, thereafter I did not visit the Black Hills again. Then in the summer of 1967, it happened that I gave a recital of poetry at Spearfish State College. In approaching the cabin again, we had paused at the point where the railroad used to pass within a few feet of our front door. Then suddenly something happened that has left me with some haunting questions. Out of the nearby brush a big handsome shepherd dog charged upon our company, obviously singling me out from the party of eight as the object of his apparently savage attack. The impact of his powerful body staggered me and I was afraid of him until he stood upon his hind legs, placed his paws on my shoulders, and proceeded to give my face an affectionate tongue washing.

The dog could never have seen me before, and his master was astonished at his unusual behavior with a stranger.

Could it be that the love of old Shep for his man had somehow descended through generations of pups?