Osborn Mountain, 7-7-07

 

There are few mountains in the Wind River Range that can be climbed in a day, and even those few are long, strenuous hikes. I chose Osborn Mountain for my first big adventure because it is close to a trailhead, high enough to afford good views, and has a large flat summit (nearly 1.5 square miles) that is easy to explore.

I set out at 9:45, a bit later than I had hoped, but I had been up late the night before and wanted to be well rested. After a long drive down horribly washboarded gravel roads to the Green River Lakes trailhead, I finally hit the trail, elevation 8000 ft., at 11 am. The first two miles were pretty level, following the beautiful lake, and I made good time and met a number of other hikers.

Toward the end of the lake, I could look eastward for great views of the area's most-photographed mountain, squaretop. This part of the range is characterized by large, flat-topped mountains with extremely steep sides. This strange topography reflects the geologic history of the range. Initially formed when a block of 3.4 billion year old gneiss rose 50,000 feet relative to an adjacent block of sandstone (along a fault which is still visible), the mountains were then eroded to form a high, relatively flat plain. Then the whole range was uplifted again, and glaciers and streams began to cut into the high plain, leaving a landscape of high, flat mountains dissected by deep valleys. Also note the haze in this photograph, a haze borne of distant fire that was the only drawback to this day, as it obscured distant views of the plains and the Tetons from the top.

At the end of the lake, my trail turned north along Clear Creek for another two miles to the Clear Creek Natural Bridge. The valley afforded spectacular views of the old fault slicing up the side of Flat Top Mountain.

Where Clear Creek crosses the old fault line, it has bored through an area of weakened rock to form the natural bridge, which resembles a tunnel much more than a bridge but is nonetheless interesting to look at. More interesting to me are the vertical markings on the polished surface of the rock above the creek - formed as this block of rock slid vertically along the fault.

From here my route left established trails to follow a small stream up Osborn Mountain. For the first 1500 vertical feet, I climbed through a forest that had been recently burned, leaving a tangle of deadfall that proved rather exhausting to move through.

Halfway up, I reached a beautiful open basin from which I observed a herd of elk on the distant forested slope. From here my route turned to the right to follow a steep creek bed to the top.

While climbing along this creek, I surprised a cow elk in front of me, though unfortunately her head was down when I snapped this photo.

I cannot do justice to the flowers in photos. They are as beautiful and as plentiful as in Colorado - perhaps more so here because all must bloom and seed in the few short weeks between snowmelt and summer drought. Many shades of red, blue, yellow, and the occasional purple or pink.

After a strenuous 1000 foot climb up the gully that left me exhausted, I had finally arrived on the summit plateau - 1.5 square miles of gently sloping alpine tundra. I reached this point shortly after 3 pm - about the time afternoon thunderstorms often move in. On this day, the morning clouds failed to develop, so I pushed on to the top.

Soon I began to find snow - all of it melting quickly beneath the warm sun and 65-degree temperatures of the day. The clouds, while still above me, were much closer to the ground than I am used to.

Though I knew that at some point I would reach a cliff, I was somewhat unprepared for it when it appeared - imagine walking along a flat plain and suddenly realizing that the ground in front of you is missing for a thousand feet down.

This cliff edged valley was carved deep in to the ancient gneiss by glaciers over millions of years. A small "glacier" remains at the head end, though I am not sure if the snow is permanent here. The cliff edge affords good views of the core of the Wind River Range, including Gannett Peak, at 13804 ft. the highest point in Wyoming - eclipsing the Grand Teton by only 30 ft.

It is hard to say exactly where the top of Osborn Mountain is, though my topo map showed it to be somewhere along the north edge of the cliffs, so I headed for that point. Near the top, the terrain is absolutely flat, making for some great easy walking at 11,800 ft. Notice also that the mountains in the distance are about the same elevation and equally flat. It is easy to forget, walking around up here, that you are on top of a mountain.

Walking toward the apparent summit, I passed a beautiful little snowmelt lake perched on the edge of a thousand-foot drop to the valley below.

As I reached the highpoint, I found one of the few pieces of evidence that humans have been here before - a survey marker marking the summit at 11,890 feet - 3900 feet above my trailhead.

I stopped here to eat the rest of my energy bars and dried fruit. I would have stayed longer but it was 5 pm and I had promised to be back at home by 9:30. So I took one last look at the cliffs...

...and headed for Mill Creek. Along the edges of snowfields, I began to notice small, unfamiliar black birds that I suspected to be rosy finches. With my new zoom lens, I managed to get a decent picture from which I later identified them as Black Rosy-finches - the only species to breed in this region.

On the north slope of the mountain, large patches of snow remained. Notice also the distant mountains obscured by the haze.

Some areas where the snow had just melted were covered in small yellow marigold-like blooms.

The way down proved more challenging than the way up. My initial descent followed a valley filled with talus, so that I was forced to hop from rock to rock. Interesting large hairy spiders build circular webs between these rocks with very strong silk - dodging these added to the adventure.

Below the talus lay a beautiful verdant meadow - better to look at than to walk through given its sogginess.

Along the creek, in only one spot, I found a patch of brilliant pink flowers with an odd characteristic - when touched they leave behind a pungent smell, neither pleasant nor unpleasant, that remains on hands and fingers for an hour.

At the end of this basin the going gets tough. At this point I was only 2-3 miles from the car, but the slope steepened and the tangle of fallen logs returned.

In the final drop down the mountainside, the creek enters a canyon between sandstone cliffs. I managed to eventually descend a steep slope into the canyon from which I took this picture of the other side.

From this point on the going was easy. Soon the forest opened into sagebrush, and I reached the car at 8:15 - exhausted but satisfied to have completed the longest and most strenuous hike of my life thus far.