Blue Mesa Sauropod Rescue
Exposures of the Morrison Formation are widespread in the Western Interior of the United States. They consist of a
distinctive series of multicolored sandstones, mudstones, and shales which were deposited on low-lying floodplains and in fluvial
environments during the late Jurassic Period. These sediments (named after the town of Morrison, Colorado, where discoveries leading to
the "bone wars" of the last century were made) are famous for the dinosaurs they contain, notably including those at Dinosaur
National Monument, which straddles the Colorado-Utah border.
My involvement with the Morrison was as part of a team from the Western Interior Paleontological Society
which was assisting the National Park Service in retrieving a sauropod which was about to drown. (Well, okay, if drowning was the cause of death,
it happened 140 million years ago, but now the fossilized bones were about to be submerged under the waters of Blue
Mesa Reservoir.) The Park Service wanted us to get out as much of the beast as we could before the reservoir swelled to its highest
level in many years, replete with meltwater from the record snows which El Niño brought to us in Colorado in the spring of 1994.
As digs go, we had it pretty cushy on this one. The Park Service let us stay in a dormitory-style condominium (cooking
facilities, hot showers at night!) and taxied us out to the site by boat each morning. The bones were embedded in the hillside near the shore
of the rez, and at the time I was there, were a good thirty feet above the water level. We disembarked from the boat, climbed the
side of a small gully, and were there. No marching miles across searing desert with heavy backpacks: these bones lie at about 7000
feet elevation in the Rocky Mountains, near Gunnison, Colorado. The scenery is spectacular and the weather was perfect for digging
-- coolish and overcast, but not much rain. When the occasional shower came we all retreated under the "Fred shed", a
tarpaulin-covered shelter named after one of the dig's leaders. We even had a porta-john available; now is that luxury, or what?
Until the bones are extracted and more fully studied, it is only possible to say that they are sauropod remains. That's one of
those long-necked, long-tailed dinosaurs, like Apatosaurus
(Brontosaurus) or Diplodocus. Which one, no one is sure. And we don't
even know yet how much of the skeleton is there. We worked on vertebrae, ribs, and something dubbed the "UFT" (unidentified
flat thing). The bones are in a matrix of mixed sandstones and mudstones typical of the Brushy Basin member of the Morrison.
This means that in some places, the surrounding rock is quite soft and easy to remove, and in other places, it's as hard as...well, rock.
Hammers and chisels were standard equipment, along with plenty of vinac, and superglue to repair damage (some done by
Mother Nature, some done by us). Many of the bones needed plaster jacketing to hold them together. Sometimes, we could remove
the bone from the rock, but the pieces didn't fit together well enough to be glued and had to be held in juxtaposition by the burlap
and plaster. Other times, the bones were too fragile to be removed from the matrix in the field, so we had to jacket large blocks
for removal. Such was the case with a series of several articulated vertebrae which extended into the hillside.
I would have liked to be out there digging day after day, but other commitments dictated that I be just one of several members of
a rotating crew. The short time I spent at Blue Mesa was a lot of fun, though. (My only complaint was of the abundance of ticks,
and a little superglue froze those in their tracks: fossils in the making). Two weeks later when I talked to Doug, the other team
leader, he told me that the water level was rising so fast that he expected the Fred shed to be underwater that afternoon. Another ten feet
-- not an impossible rise in a day when the snows melt -- and the bones would be flooded. Some of the blocks we removed
were estimated to weigh over two tons, and it was touch and go whether they would be too heavy to be loaded on the Park Service boat.
Doug was trying to get through to Fort Carson to see if he could borrow a helicopter so he didn't have to winch the blocks up
the hill to avoid the rising waters. (Fortunately, as it turned out, the boat did manage to hold even the largest block.) As for the rest
of the sauropod, well, he's blowing bubbles by now, waiting for us to return again when the water is lower next spring.
