October 8, 2010

Scottsbluff National Monument, Nebraska

Today we visited Scottsbluff National Monument in western Nebraska. Scottsbluff was an important spot along the Oregon Trail, as it marked the first major change in the landscape after 600 miles of flat monotonous Great Plains grasslands. After the hardships of 2 months of never ending flatness in 90 degree heat, awful mosquitoes, vicious thunderstorms, and the constant stench of dead oxen on the trail, this was a welcome sight that things were about to change.

View of Scottsbluff from the Visitor Center with brewing storm in the background
At truly the edge of the west, Scottsbluff stands 600 feet above the surrounding plains. It's summit represents the original level of the Great Plains approximately 5 million years ago. 70 million years ago, this region was under the Cretaceous seaway. But, as the Rocky Mountains began to rise for the first time, sediments washed down and began creating an enormous gradually descending plain. The top of the bluff represents sediments deposited about 19 million years ago.

Rising above the plains
As the sediment deposition lessened, the rivers flowing from the Rockies (in this case the North Platte River), began to remove much of this previously deposited sediment and lowering the elevation of the Great Plains. Scottsbluff, containing some rocks more resistant to erosion than the rest, remains above the plains.

We did the 1.6 mile hike to the top of the bluff from the visitor center with a brewing storm above. It seemed like we had just enough time to get up and back. Indeed we did, as the rain started as we arrived at the visitor center.

Layers of volcanic ash, river muds, and wind blown sands of the Great Plains deposition

The visitor center and Mitchell Pass, where the wagons passed through the bluffs
For those traveling the Oregon Trail, Scottsbluff represented the 1/3rd mark of their journey. On its summit were the first ponderosa pines they would have seen (and thus the ecological beginning of the west). Just about 100 miles to the west lay the Rocky Mountains, which are visible from the top of the bluff on a clear day. We did make out 10,200 foot Laramie Peak in the far distance in Wyoming.

Another sign of entering the west are these arid plants, such the yucca and cactus. Scottsbluff, in the rainshadow of the Rockies, and not quite far enough east to get significant rainfall off the Gulf of Mexico, only gets around 15" of precipitation per year.

In this shot, you can see the flatness of the Great Plains heading off into the far distance, with the city of Scottsbluff in the near distance. The Missouri River is 600 miles and 3,000 feet elevation away.

Heading back down to the visitor center
It would have been such a challenge to have made the Oregon Trail. I doubt most people knew what they were getting themselves into and I am sure the business men who profitted from it didn't want them to know. The video at the video center talks about a traveler who realized that he didn't need to bring anything with him. All he needed to do is start out with an empty wagon and pick up supplies along the way, as people jettisoned everything along the trail to lighten the load for their overworked oxen.  But, the worst part is imagining the strench and vision of thousands of dead animals (and people) along the sides of the trail rotting in the hot humid sun across the state of Nebraska for two months of monotonous travel.

Sunset View of Scottsbluff from the Campground
Alas, our trek across the west comes to an end soon. We are sort of making the migration in reverse. You'll have to keep watching this blog to see where we head next. I can tell you one thing, it'll be new territory for all of us.

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