A FOREST OF STONE 



By F. H. KNOWLTON, United States Geological Survey 



REMARKABLE fossil forests exist 

 in Yellowstone Park, the most 

 remarkable, it is believed, of the 

 several fossil forests which have 

 been discovered there are others in 

 Egypt, in California and in Arizona 

 because in the Yellowstone most of the 

 trees were entombed in their original 

 upright position and not found recum- 

 bent and scattered about the ground. 

 In Arizona, for instance, the fossilized 

 trunks have evidently been carried a 

 long distance from where they origi- 

 nally grew. In the Yellowstone the trees 

 now stand where they grew, and where 

 they were entombed by the outpouring 

 of various volcanic materials. Now as 

 the softer rock surrounding them is 

 gradually worn away they are left 

 standing erect on the steep hillsides, 

 just as they stood when they were liv- 

 ing; in fact, it is difficult at a little dis- 

 tance to distinguish some of these 

 fossil trunks from the lichen-covered 

 stumps of kindred living species. Such 

 an aggregation of fossil trunks is there- 

 fore well entitled to be called a true 

 fossil forest. It should not be supposed, 

 however, that these trees still retain 

 their limbs and smaller branches, for 

 the mass of volcanic material falling 

 on them stripped them down to bare, 

 upright trunks. 



These fossil forests cover an exten- 

 sive area in the northern portion of the 

 park, being especially abundant along 

 the west side of Lamar River for about 

 20 miles above its junction with the 

 Yellowstone. Here the land rises rather 

 abruptly to a height of approximately 

 2,000 feet above the valley floor. It is 

 known locally as Specimen Ridge, and 

 forms an approach to Amethyst Moun- 

 tain. There is also a small fossil forest 

 containing a number of standing trunks 

 near Tower Falls, and near the eastern 

 border of the park along Lamar River 

 in the vicinity of Cache, Calfee, and 

 Miller Creeks, there are many more or 

 less isolated trunks and stumps of fossil 



trees, but so far as known none of these 

 are equal to the fossil forest on the 

 slopes of Specimen Ridge. 



The fossil forests are easily reached 

 over the wagon road from the Mam- 

 moth Hot Springs, or from the Wylies 

 Camp at Tower Falls, and they are in 

 their way quite as wonderful and worthy 

 of attention as many of the other fea- 

 tures for which the Yellowstone Na- 

 tional Park is so justly celebrated. 



Recently another extensive fossil for- 

 est has been found on the divide between 

 the Gallatin and Yellowstone Rivers in 

 the Gallatin Range of mountains, in 

 Park and Gallatin Counties, Mont. 

 This forest, which lies just outside the 

 boundary of the Yellowstone National 

 Park, is said to cover 35,000 acres and 

 to contain some wonderfully well pre- 

 served upright trunks, many of them 

 very large, equaling or perhaps even 

 surpassing in size some of those within 

 the limits of the park. 



In the beds of the streams and gulches 

 coming down into the Lamar River 

 from Specimen Ridge and the fossil for- 

 ests one may observe numerous pieces 

 of fossil wood, which may be traced for 

 a long distance down the Lamar and 

 Yellowstone Rivers. The farther these 

 pieces of wood have been transported 

 downstream, the more they have been 

 worn and rounded, until ultimately 

 they become smooth, rounded "pebbles" 

 of the stream bed. The pieces of wood 

 become more numerous and fresher in 

 appearance upstream toward the bluffs, 

 until at the foot of the cliffs in some 

 places there are hundreds, perhaps 

 thousands of tons that have but recently 

 fallen from the walls above. One trav- 

 ersing the valley of the Lamar River 

 may see at many places numerous up- 

 right fossil trunks in the faces of nearly 

 vertical walls. These trunks are not 

 all at a particular level but occur at 

 irregular heights; in fact, a section cut 

 down through these 2,000 feet of beds 

 would disclose a succession of fossil 



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