Last year, we did a loop hike along Thielsen Creek in the Mount Thielsen Wilderness. Our report on this (post) triggered some comments about the spring (shown on the USGS and USFS topo maps for this area) in the large pumice basin immediately east of Mount Thielsen. So, last week, we explored a cross-country path from the Howlock Mountain trailhead to Thielsen Meadows on the Pacific Crest Trail (PCT) and then up to the Sawtooth Ridge overlooking the pumice basin – it’s actually called Cottonwood Creek Basin and is an area with unique botanical species (post). At that time we decided not to press on down into the Basin to actually see the spring. It was the right decision then but it left unfinished the business of actually seeing this fabled spring. So yesterday I went back up there to rectify this situation.
After parking at the Howland Mountain trailhead, it was back through the tunnel under Highway 138,
along the Howlock Mountain trail and across delightful Thielsen Creek,
and then up the Thielsen Creek trail to the PCT and the start of the cross-country portion of the hike. The return to this point was speeded along by recent trail maintenance that had cleared all the downed trees on the Thielsen Creek trail (Yeah! And thanks!). Going cross-country up the headwaters of Thielsen Creek gave me another stunning view of the contorted geology that defines Mount Thielsen.
The mosquitos were moderately bad on the trail – not bad at all IF I kept moving – but once I moved on to the snow for the final climb to the Sawtooth Ridge, these winged vampires pretty much disappeared. There was, however, one bee or wasp that pestered me relentlessly all the way to the Sawtooth Ridge, snow or no snow.
Soon I was once again on the Sawtooth Ridge. From there, I had a great view of Diamond Peak to the west,
and of today’s objective – Cottonwood Creek Basin – below me to the east.
It’s about 600 feet down the eastern slope of the Sawtooth Ridge to the Basin. I accomplished the descent down this rather steep slope by first contouring north on open ground and then going almost directly down through the trees (if you go straight down from the Sawtooth Ridge, you’ll run into an awkward-to-cross boulder field). And, by following this route back up, the 600 foot return climb turned out to be a lot less painful than expected.
Once down, I got a full view of the rarely seen eastern face of Thielsen – one truly twisted piece of volcanic rock – which looms over the Basin.
The aerial photos I’ve seen of this side of Thielsen don’t capture the incredible mix of rock types that makeup this face: columnar and smooth basalt all twisted together.
Nor such details as this huge “cave” (maybe a “popped” bubble of molten basalt?), now oozing water and greenery on to the lower face.
Nor do they capture the colorful convolutions of lava that form Point 8457 to the south of Thielsen’s summit.
The floor of the Basin is a parched expanse of pumice, gravel, and sand, with nary a drop of water in sight. But this is really 20 to 30 feet of porous rock that captures the entire drainage of the Basin, drains it down to an impermeable layer, where it then flows to daylight at the springs. This is not to say there isn’t overland flow at some points in the year but it’s this groundwater that seems to sustain the creek and the falls.
I pushed on along the north side of the basin toward where the spring is shown on the map, through some terrain that didn’t look anymore “wet” than the Basin behind me.
I dropped into an unusually flat channel that may have been formed by occasional flushes of water,
and followed it out and around to a view of a green area sporting not one, but two, springs!
The “southern” spring flows out from beneath the pumice over toward Point 8457,
while the “northern” one does the same more in line with the Sawtooth Ridge.
Although each is only a few inches deep at the start, their two flows soon merge together in a small meadow,
and then, in combination, become Cottonwood Creek.
I soon started to hear what sounded like a waterfall but nothing of the sort was visible at this point. So I kept going east, following the new creek to where it suddenly leapt over a lip,
and became Cottonwood Creek Falls!
I like waterfalls in general but not obsessively. Still, I was almost stunned by my first look at Cottonwood Creek Falls. Maybe it was the effort it took to see them, maybe it was the unexpectedness of them existing only a few hundred feet from a (seemingly) waterless expanse, maybe it was the cool breeze and spray they wafted over me, maybe it was the little rainbow at the base of the falls. Regardless, seeing them was totally worth it. Amazing!
After this drop, the terrain that created the Falls starts to level-out a bit,
and the Falls become a cascade that runs off down the valley for a half-mile or more.
After this, it was all anti-climax as I retraced my steps back up the slope to the Sawtooth Ridge.
After that, it was all downhill over easy cross-country and good trail back to the car (and the mosquitos that had waited there all day for another shot at my vital fluids…). There are five things about this hike (14.3 miles round-trip (mostly on trail); 2,800 feet of elevation gain – 600 feet of which is getting back out of the Basin) that make it (IMHO) one of the premier hikes in this wilderness: (1) the Divide, with its fun cross-country approach and big views, (2) the contorted eastern face of Mt. Thielsen, (3) Cottonwood Basin, 30+ feet of porous rock over an impermeable layer, (4) the springs (yes, there are two) that come from beneath the pumice as trickles and within 100 yards are a creek, and (5) Cottonwood Creek Falls (WOW!). The Falls are a worthy destination but one that seems to only get mentioned in passing or with generalities. But I found a 1998 notice of an Oregon Native Plant Society of Oregon 3-day/2-night backpack to the Basin, so I suspect they’ve been a local “secret” for sometime. The drive home featured a stop at Beckie’s in Union Creek to pick-up one of their delicious apple pies!