A Visit to Stone Mountain

From the road along the east side of Groundhog Mountain, there is a great view of the cliffs at Stone Mountain less than 3.5 miles to the northwest.

Stone Mountain is a popular geographical name, especially back East, but amazingly enough, there is only one Stone Mountain in Oregon. It’s in Lane County, just east of Hills Creek Reservoir. There are no trails, but there is a road leading right to the quarry at its base at around 3500′. From nearby Groundhog Mountain last month, I got a good view of the striking 300-400′ cliffs on the east side above the quarry. With all the great plants I’ve seen at Groundhog Mountain, Moon Point, and Youngs Rock, I wanted to not only check out these irresistible cliffs but also to explore this area just a bit to the north of my usual haunts. Yesterday (November 12), the pleasant dry weather gave us a good opportunity, so Sabine and I drove out to Hills Creek Reservoir south of Oakridge to see what we might have been missing.

A grand sugar pine (Pinus lambertiana) showing its attractive reddish plated bark

On Google Maps (click here to see), the south side of Stone Mountain shows a series of open ledges. As cold as it was, I thought we’d drive out Road 479 and check out this lower and warmer area first. We couldn’t see the ledges until we passed them and drove farther uphill where we could look back and see they were higher up than they appeared. It would take some difficult bushwhacking to reach them, and with plentiful poison oak at this elevation, it did not seem worth trying. The roadcuts were also a disappointment. Where there were rocks, they looked like some sort of a crumbly mudstone (just a wild stab from a geologically ignorant naturalist). Whatever they were, they were largely devoid of plants except for a pretty stretch with many silvery leaves of Lupinus albifrons. What we did find of interest was a large population of sugar pines (Pinus lambertiana). We knew they were in the area—there are a couple on the Youngs Rock trail and along Road 21 near Mutton Meadow—but most places we’d seen them, there were just a few isolated trees. We eventually counted a few dozen very large trees, and happily, many more healthy youngsters coming on, especially along the road banks where many Christmas-tree-sized plants were taking advantage of the more open conditions. Even on the Larison Rock trail, just northwest of the reservoir, where there are a decent number of mature trees, I remember not being able to find more than a couple of saplings. Many impressive foot-long or more old cones lay beneath the larger trees.

The buds of hoary manzanita (Arctostaphylos canescens) have long bracts like the very similar hairy manzanita (A. columbiana).

There were also many pretty evergreen hardwoods along this road including madrones, chinquapins, and lots of manzanitas. I checked many of the manzanitas up close, and they all appeared to be hoary manzanita (Arctostaphylos canescens). Quite similar to hairy manzanita (Arctostaphylos columbiana), this species differs mainly in the lack of long coarse hairs on the stems. Its softly pubescent stems held many buds, promising a good flowering of pretty pale pink bells in early spring. This species is near the northern edge of its range here in southeastern Lane County (see OregonFlora map).

Next, we headed up Willow Creek Road 2703 along the north side of Stone Mountain (We think Road 479 should be named Sugar Pine Road). Here Ponderosa pines (P. ponderosa) were much more common. We noticed Ponderosas seem much more inclined to grow in close stands. In addition to their much longer bundles of three needles, their gorgeous cinnamon bark has bigger “puzzle pieces” than sugar pine, and their branches are noticeably curved. There were a great many mushrooms along the side of the road, with some large clumps of golden toast-colored fungus and some unfamiliar ghostly white toadstool type. We even came home with a handful of chanterelles.

With enough sun, shinyleaf gooseberry (Ribes roezlii var. cruentum) puts on a great show of autumn color.

It was quite easy to find the quarry at Stone Mountain, only 1.5 miles off of 2703 on Road 475. Up close the cliffs were indeed impressive. A quick scan with the binoculars revealed mostly just Sedum spathulifolium and some rock ferns. Then I noticed the gray, broom-like stems of rabbitbrush (Ericameria nauseosa). They were all over the southern end of the cliffs and along the quarry roads as well. I managed to bushwhack my way to the base of the cliff on the south edge and was happy to see there were more species than could be seen from a distance. Penstemon rupicola and Lomatium hallii would make a colorful show next year. The thorny branches of shinyleaf gooseberry (Ribes roezlii) were everywhere. Their darling fuchsia-like flowers are a favorite of early spring rocky areas. Large dried-up clumps of Northern buckwheat (Eriogonum compositum) grew in the piles of gravel. We took a brief walk around the north side along a logging road and found at least four plants of Viola sempervirens with out-of-season, pretty yellow blossoms. There were lots of red-flowering currant (Ribes sanguineum) plants in this area as well.

Snow has begun to blanket Groundhog Mountain, 2000′ higher in elevation. The extensive logging up there is more obvious this time of year.

I definitely want to return to Stone Mountain to see it in bloom, discover what deciduous plants weren’t out now, and to see if I can climb up the steep south-facing slope. At this low elevation, this might be a good place to explore before my other sites melt out. The snow has already hit the higher elevations. We could see plenty of it up on Groundhog Mountain. It was a far cry from our last outing, a couple of weeks ago during the warm spell, when I was able to peel down to my t-shirt up on Mount June at 4600′. It was quite chilly here in mid-afternoon. I wanted to follow 2307 to the east until it reached Road 23, as I’d never been on that stretch. I wasn’t expecting to be high enough to reach the snow, but the road took us a little above 4000′, and there was more than a dusting of snow for at least a mile. We weren’t the first to drive across it, and it was much thinner on the road, but I would have turned around had it been at all deep. I hope we get some more nice weather, so I can keep exploring the lower elevations, but I’ll just have to be patient and wait for spring to return to the higher mountains.

5 Responses to “A Visit to Stone Mountain”

  • Kris:

    Hi Tanya, beautiful pictures and interesting observations, as usual. And blooming violets at this time of year! Cool!

    I’m glad that you and Sabine were able to get out and enjoy the dry weather.

  • Great photos! I came across some sugar pine cones on the trail at Table Rock Wilderness. It was a rainy, socked in day and I never got a good look at the trees themselves. I was surprised to find evidence of sugar pines. I assume they are somewhat rare in the Western Cascades?

  • Hi Ivan,

    North of Douglas County, it is uncommon to find these beautiful trees. Good find! I haven’t seen sugar pine at Table Rock Wilderness, only white pine, and there doesn’t seem to be a record of it on the Oregon Flora Project Atlas. Do you remember the part of the trail where you saw the cones?

  • Well, now I am wondering if the cone I saw was actually from a white pine. Here is a link to a photo I took of the cone. What do you think?

  • Hi Ivan,

    The cone in your photo does look pretty straight like a sugar pine. How long was it? Next time you’re back at Table Rock, try to find the tree. Sugar pine bark is very different from that of white pine.

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