YELLOWSTONE
Trailside Notes (Number One) 		NPS Logo

TRAILSIDE NOTES

II. Norris to Madison

After taking the geyser walk and visiting the Trailside Museum at Norris we set the mileage at zero and continue our journey down the valley of the Gibbon.

NOTE: The text is arranged in three columns. Objects on the tourists' right are described on the right-hand side of the page; those on the tourists' left, on the left-hand side. Objects in front and general descriptions occupy the middle of the page.

Due to changes in the road, distances as given are only approximately correct. Government markers by the roadside give more exact distances.

Web Edition Note: Due to numerous changes in the years since this guidebook was published, the text should solely be used for historical purposes.
MILEAGE
MILEAGE
0.3 0.3

Presently we enter Echinus Basin (Echinus is Greek for spine). In this area the hot waters seem inclined to cover everything in their neighborhood with spines. If you dismount, be careful. The crust is thin in places.


Minute Geyser on the left plays spasmodically to a height of 15 to 25 feet. Monarch has abdicated and trees are beginning to grow on the walls of its crater.
1.0

ELK PARK

The encircling hills are largely the remains of lava flows. This is one of a series of beautiful meadows—a filled lake bed—through which the Gibbon River leisurely meanders. In the early morning and late evening deer and elk may be seen.

 1.0
1.3 Mount Holmes rises majestically above the plateau. To the extreme right a bit of Electric Peak pierces the horizon. 1.3
1.7 We enter a dense stand of Lodgepole pines. 1.7
2.3 At the Gibbon Cascades we stop at the turn out and dismount. The rhyolite at the left has a purple shade. At one time it doubtless extended as a dam to the other side of the river. The acidic waters often undercut the boulders making what are called "duck rocks." Walk back a bit and note that these undercut rocks are on the higher banks on both sides of the river. This is evidence that the river, not so very long ago, was much higher than it is at present. The cascades are tumbling over horizontal layers of rhyolite in their work of lowering the channel.

2.3
2.4
Drive ahead to the Chocolate Pots. Note—100 feet down stream—a miniature geyser forcing its jet up through the river.
2.9

GIBBON MEADOWS

Black patches of rock on the encircling hills, rising steam, and the walls of the gorge that we are about to enter argue that we are still surrounded by and are motoring on and through huge masses of volcanic rock that have invaded Yellowstone from some unknown source. This is the largest of the filled-in lake beds which we shall meet while motoring down the Valley of the Gibbon.

Monument Geyser is probably steaming away on the top of the elevation at the right. Why did it not find a vent at a lower level?

Another fine view of Mount Holmes.

 2.9
3.6
At the foot of Paintpot Hill—about one-half mile from the road—are a series of hot springs and pools having most brilliant colors—the brightest in the Park.
4.0 Leaving the meadows, we enter Gibbon Canyon. We dismount at the little rustic bridge. The frowning walls at the left recall those that we saw at Obsidian Cliff, but on closer examination of the boulders we find a greater variety of structure. The molten lava that flowed down this valley must have come from a different source, contained a different ratio of elements, had a different rate of cooling, and the flow probably occurred at a different time. If we do not attempt Monument Geyser we proceed down the gorge. 4.0
4.3
Note the flowing lines assumed by the lava as it cooled.
4.4
Thermal activity is evident at Stone Bridge. Lodgepole pines seem to enjoy growing out of rocks in a most impossible way. A lot of geological events have taken place here.
4.8
We stop at Beryl Spring—an agitated cauldron. Sulphurous steam rises from the vent. The rock in the cut just beyond the spring is an agglomerate.
5.2
Look up at the left wall of the gorge and imagine the hot viscous, lava creeping slowly down.

The white rock, just above the river, looks like travertine or sinter. We wonder if it marks a hot spring.
5.5
More white rock. Hot water is certainly extracting something from below and depositing it on the surface.

At one time a mass of debris was being forced into the valley at this point. Note the variety of rocks in the exposed bank.
5.6
We approach a stone bridge and face a grand buttress of pinkish rhyolite.

Coarse glacial debris on this side.
6.5

Before crossing the cement bridge note, high on the right, the cross-seaming and checkerboard cracks in a majestic cliff—a part of Purple Mountain. Along the flank of this mountain we will motor for several miles.

See how one mass of rock has slid over another and smoothed its surface.
7.5
Further evidences of the glaciers' craftsmanship.
7.8

Splendid "annual layers" being destroyed by percolating water. A lake must have been here. The successive layers of clay represent successive years of deposit in the bottom of a glacial lake.

More "annual layers" and hence more evidence of a lake or pond.

This exposure is said to be one of the best in the country. It is estimated, by counting the several layers, that there are at least a thousand years here recorded.

A splendid cross-section of a river bottom. It evidently cut right through an earlier lake bottom. It shows minor faults or slips.

A brook from Secret Valley comes in from the right.

We face a wall of firm rhyolite. Blasting has removed the older face of this wall. Compare the new artificially exposed surface with the older natural exposure at the right. We pass another mass of glacial rubble.

8.2GIBBON FALLS
We dismount. This is where the river drops eighty feet from one layer of lava rock to an other. From what we have just seen, and from the appearance of the banks, the work of a glacier and its underlying mud and boulders are strikingly exhibited.

The boulders attain amazing proportions.

For half a mile we pass along a great variety of river and glacial deposits. All these have one thing in common, viz. a great variety in size, composition, and lack of bedding of material from the heaviest boulders to the finest clay.
9.3—10.6
We pass more exposures of the rhyolite of Purple Mountain.
10.9 We pass through an avenue of Lodgepole pines. National Park Mountain looms ahead. 10.9
TUFF CLIFF FIELD EXHIBIT11.5

Dismount and follow trail to base of "Honey Combed" Cliff

The tuff or volcanic ash is a very soft, friable rock. In many places it has been weathered out leaving holes and gullies. The cliff would have been washed away entirely if not protected by a cap of rhyolite. Test the relative weight of tuff and rhyolite. The first descended from the air, the second ascended from below.

12.4
The Gibbons flows at our left—note the verdant meadows.

The road emerges from the forest and a beautiful scene is spread before us. Purple Mountain on the right with its series of peaks, the vertical wall of Madison Canyon in front, flanked on the left by National Park Mountain.


12.5 Terrace Spring on the right and left, cascades from one level to another like the hot springs at Mammoth. For some time the terraces at the left were dead, but a recent change in the course of the warm brook leading to them has vitalized them and they are now radiant with color. Both sinter and travertine are deposited. 12.5
13.4

TRAILSIDE MUSEUM
MADISON JUNCTION

We park in front of and visit the Trailside Museum at Madison Junction. Here we will find an interesting history of the paths taken by the early trappers and explorers and a full account of the work of the Washburn-Langford Exhibition of 1870.

The scenery at Madison Junction should receive attention. It is also one of the best places to illustrate an important event in the geologic history of Yellowstone. After the flows of rhyolite had been poured out to a depth of hundreds of feet they did not remain horizontal sheets. The earth's crust broke into large blocks and—in tilting unequally—exposed steep cliffs at their edges. Rivers naturally sought these fractures. It is at the base of cliffs and other exposures that we have been winding our way. Madison Junction is thought to be the meeting place of fractures between three major blocks, the cracks having been widened by glaciers during the Ice Age.

If you examine the relief map in the Museum, you will see that one of these blocks lies in the angle between the Madison and the Gibbon Rivers. A second lies in the angle between the Madison and the Firehole, and the third is the eroded Central Plateau.

The Madison River flows in the crack between two huge blocks of the earth's crust.

 13.4

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Last Updated: 02-Apr-2007