Up a short trail from the Red Town entrance to Cougar Mountain Park, there is a coal mining exhibit, with a coal car, a mine shaft, and signs with pictures of the coal operations and maps of the coal works. It is hard to believe that there was so much going on here, and now it seems, at least superficially, to have reverted to wilderness. There are hints, such as the giant mine shaft almost a mile and a half away from the other mine works. Could that really be connected underground with the other entrance?
I set out to find out more about the mining operations. I started in the local B&N, with the “Images of America” books on Issaquah. That has a few pictures, with some impressive buildings and towns, but little hard information, other than the fact that there was constant strife between the miners and mine owners.
Next I turned to a geologic map of Issaquah, which shows where the coal seams run through the park. Yes, indeed, the coal seam runs under the Red Town entrance, runs under Cave Hole Trail, and continues on up to where the shaft emerges near the clay pit. So it is possible that the mines followed the seam all the way.
But what about those trenches, fissures, whatever, on the east side of Claypit Peak? There is one near the top, and others half way down. They are perpendicular to the direction of the seams, not along them as I would expect. Maybe they were searching for the seams? A clue in the references section of the geologic map led me to the Washington Division of Geology and Earth Resources (website). There I discovered a fascinating report, written in 1912, on the coal mines of King County. It turns out there were mines in Issaquah proper, in Newcastle (the mines at the Red Town trailhead), and in Renton. These were all tapping into the same seams. Here are some pictures from that report.
And there was a map of the mine itself. This same map is posted on the mining exhibit, but I have never been able to study it carefully because of the cold, the rain, or the patience of whoever else I am with.
But the very best was that the report appendix had a contemporary geologic map. Here is a part of it.
This shows the mines extending from Red Town toward the (current location of the) clay pit, but do not show any activity where I have observed the trenches, which would be in the middle of square 31 and to the left (west) in square 32. But they do lie roughly along the path of the coal seams, which can be presumed to continue their path from Red Town to Issaquah.
One thing I have learned by studying the geologic map is that there is a distinct change in the composition of the bedrock running roughly E/W through the park. On the one side is a layered shale and coal rock, and on the other a much harder formation made up of volcanic sandstone, volcanic ash, and lava flows. I have wondered about the cleft, seen so clearly with Google Earth, between Wilderness Peak and Claypit Peak, down which Newcastle Queen Creek flows. It turns out that the boundary between these formations lies almost exactly along Newcastle Queen Creek. I guess the steepness of the whole southern part of the park owes to this harder lava-based bedrock. It seems, too, that the vegetation is different across this divide, but that may be my imagination or it might be due to the pattern of logging that took place.
Other interesting publications on the same website: A 1984 report on coal mining in Central Kings County, containing this map:
Finally, in this publication, I found the most detailed map of the Cougar Mountain Coal mines:
The Red Town trailhead is in the upper left. The mine shafts appear to be denoted by a square with the top-left corner colored in. The shaft near the Red Town trailhead is visible, near the number 17. The air shaft near the clay pit is also visible, in the center. The tunnels do actually extend that far, and beyond, and in fact extend as far in the other direction as well. The air shaft, mentioned in the Wikipedia article, is also shown near the number 28 on the far right.
Of interest are the little Y-shaped lines perpendicular to the coal seams. Near Claypit Peak, and on the far right, there are many of these labeled “incomplete”. Near the Newcastle-Queen Mine Trail there are several as well, shown connecting to the coal seams. These appear to be tunnels, allowing access to the mine from the surface. If so, this suggests the trenches are collapsed mine access tunnels. I guess that would kind of make sense.