Grandpa's irrigation ditches left deep gashes in the side of Week's Hill. Vaguely conscious that a great lake had once covered the entire valley, I became fascinated as a child with the fact that the layers of clay and sand in the irrigation washes had been laid down in a time so long ago that it was hard to comprehend. Yet, there it was, before my eyes.
I remember the feeling so well, of curling up against the clay walls, in the cool of an afternoon shadow, and with a fingernail scraping at the sand and thinking, "This sand is like a silent witness, a calendar of a time so long ago that it is unbelievable. The last time this sand was stirred was the day it settled in the bottom of that mystery lake that existed here so long ago.I remember thinking how neat it would be to find something more than just the sand. A leaf, maybe. Or a bone. Or, beyond all my imaginings, a skeleton of some prehistoric animal that had settled there and now was being revealed as irrigation water cut away at this clay calendar of time.
So when I read an article in the Deseret News telling that the remains of a giant Pleistocene ground sloth had been found in a sandy bank in Orem, I just had to see it.
Fortunately, state paleontologist Dave Gillette figured there would be a few nuts like me and opened the site for public viewing one whole day, right in the middle of the four or five days it took to remove the skeleton.
When I arrived, they had just exposed a femur and were carefully dissolving with vinegar the gravel around a huge kneecap. As Dave and his assistants worked, they explained to those of us behind a timid barrier of yellow "Police Line - Do Not Cross" ribbon the story of this particular ground sloth, as they perceive it might have been.
Somewhere between 11,000 to 14,000 years ago, the surrounding mountains were virtually the same as now, except they rose abruptly from the waters of the lake, which covered most of the state. About that same time, the lake broke through a natural dam in southern Idaho and drained into the Snake River for a long time, dropping its level somewhat and leaving broad deltas along the base of the mountains. Much of the eastern part of Sandy City is what remains of that delta as well as the city of Orem.
Well, our particular sloth, whose pelvis was in full view before our very eyes, was probably somewhere up the Provo River when he kicked the can and drifted down river.
The river, instead of cutting south after exiting Provo Canyon in the deep, broad valley it now flows along, shot out across the delta to a mouth on the west edge of the Orem bench. There, the sloth was deposited on the broad edge of the delta and buried in gravel, probably during the spring flood season.
One of Dave's assistants described how he probably had all kinds of stuff growing on him, a traveling apartment house for algae and grubs. They assume this because his small cousin, the tree sloth, still extant in the Southern Hemisphere, is very slow due to a very low metabolism and, consequently, picks up lots of hitchhikers. Our sloth, because of his size, would have been slower still.
I can picture him now, dragging himself along the low hills, walking on the pinky claws of his rear feet, picking at the vegetation as he went. Though he averaged a thousand pounds, he had cousins in South America that weighed in at over 3,000. By the time of his death, his species was almost extinct.
Ron Robinson discovered our friend in the gravel several weeks ago when he found a single bone on the surface and showed it to his brother, a geologist. They experienced what I always would have liked to but never thought I would.
But at least I saw him, and in the hour or so that I sat and marveled at his history, a suppressed desire of my childhood was being played out. All in all, it was a very special afternoon, thanks to Dave Gillette, his associates, and the Utah County Chapter of the Utah Statewide Archaeological Society, who were giddy enough to share the discovery with the rest of us.
- Dennis Smith is an artist and writer living in Highland, Utah County.