Tioga Corridor

NPS opens the Tioga Pass Road on 1 July. Our big snow year made clearing snow, avalanche zones and downed trees more laborious than usual. Because water and wastewater systems in Tuolumne Meadows both have problems, it's not easy to have park staff living up there yet. These important people are needed to staff the entrance gate, patrol the road, provide information to visitors, oversee Wilderness access and permitting with backpackers, patrol trails, manage a huge campground, clean public restrooms, set up seasonal housing and make sure that all utility systems are functioning well. It's been our disappointing experience that when the Tuolumne Meadows area isn't staffed by NPS, some visitors can be more destructive to the high country's values.

The partial opening of Tioga during the past week, with one-hour morning and afternoon windows is something new. While cars can't stop on the transit (except to drop-off or pick-up backpackers with permits), the windows have been heavily used by visitors and locals moving between eastern and western California.

NPS has generously allowed bicycles to ride Tioga during all daylight hours. This is one of the best bike rides on earth and is a terrific national park experience. Birds, running water, and the purr of bike tires - so nice!

Of course, as mentioned elsewhere, Tioga is open all year - just not to vehicles. Plenty of people travel this corridor all through the winter months. Those contemplating hikes in the next few weeks should expect lingering snow, difficult creek crossings, and wet, muddy trails. We hope that visitors will be gentle on the landscape as it dries out.

Post-winter Recovery

Springtime is making its way uphill in the Sierra with redbud peaking in El Portal now while unfathomable snow persists above 7000 feet. It can hardly be said enough: WHAT a winter we've had here! Storms were repeated with good frequency and lots of Pacific moisture, leaving us with a tremendous snowpack. The snowline was a bit higher than historical averages; not much accumulated in Yosemite Valley (though we had lots of rain runoff), but higher elevations have had fantastical quantities. The central Sierra has 175% of usual water content in the current snowpack. Picture the meadows and forests in the May Lake area buried by 6-7 feet of water (not 6' of snow, but 6' of standing water) - that's the nature of how much mature, dense snow is covering the tens of thousands of acres of Yosemite's upper elevations.

<-Bridalveil in flood.

Storm damage has been considerable in/near the park, with Hwy. 41 having been closed for a month by a washout, and crews working hard to repair slope movement on the Big Oak Flat Road below Crane Flat in hopes of getting it re-opened before Memorial Day. Trails at and above the Yosemite Valley level have a lot of downed trees; trail crew sawyers will be very busy for much of the summer to get those cleared. When you visit the Valley, check out the fragments of bark-less logs below Bridalveil or Yosemite Falls from trees that were uprooted and thrown over the falls this winter. Since December there's been a huge deposit of frazil (wist) ice below Yosemite Falls, and we're now in the month when one is most likely to be able to observe wist ice flowing.

The excitement isn't over. Because of the closure of the Big Oak Flat Road, Hwy. 140 has been handling much more traffic. This past Saturday, visitors were waiting over 2 hours in a 3.5 mile-long line of 800+ cars just to get through the stoplight at the Ferguson rockslide detour west of the park. (Easily avoided by coming in before 9am on weekends.) Because of the road construction in the Valley, the main parking at Yosemite Village will be closed for the next two months, and detours are confusing to both new and veteran visitors. It's going to be a very nice improvement once it's completed, but parking and navigating can be challenges on spring weekends now. Half Dome Village and the new lot by Camp Four are best bets. The road crew is already working to clear Glacier Point Road.

But, wait, there's more. The Merced is running almost 4x average flow today. All that snow in the high country seems likely to bring us some degree of 'high water incident' between now and mid-June (sure to cover some Valley trails at least), depending on how the warming progresses. Yosemite explorers should expect a delayed start to summer, with Tioga Road opening late, trails covered by snow and fallen trees, and creeks difficult to cross.

Finally wet

After being dry for nearly two months we have a series of storms coming through Yosemite. Light precipitation overnight left snow down below 7000' in places. More accumulation is expected over the next few days, perhaps as much as 2-3 feet at high elevations by Monday.
Tioga Road is closed. Glacier Point Road is closed. But the snow level is high enough that we don't have any chain restrictions in effect. Badger Pass, at 7200' has a ways to go before even cross-country skiing will be possible there.
The Merced River had gone down to 27 cfs at Pohono Bridge - a mere 20% of normal flow! The tiny bit of overnight rain is showing up in the river already with a slight rise. Last night was quite a bit warmer than usual due to the cloud cover that limited radiational cooling. Some of the many frozen waterfalls that have been so visible for the past few weeks are softening up in the warmth and rain.
While Tioga was open, park resources people made some sound recordings of the lake ice on Tenaya, Dog and Lower Cathedral Lakes. If you were up there, you know how eerie those creaking, groaning, pinging sounds were. I hope they'll have some of these unique recordings available online soon.
Meanwhile the dry landscape is soaking up liquid moisture and stacking up the solid form for later use...

Hermit and Porcupine

A bright male hermit warbler was a highlight of yesterday's birdwalk in the Valley. He was in a black oak in the company of several yellow-rumped warblers, a black-throated gray warbler and a Wilson's warbler. We love these springtime collections! Orioles have been silent and invisible this week- did they leave the Valley for lower elevations?
As part of their training on Wednesday park ornithologist Sarah Stock had interpretive rangers out in Ahwahnee Meadow looking at peregrine falcons coming and going from their eyrie up on the Rhombus Wall. She's teaching a terrific "Hawks and Owls" Yosemite Outdoor Adventure program, June 3-5, in the company of great gray owl specialist Joe Medley.
The river and waterfalls are below average volume now but will surely creep back up with a couple warm days here. More clouds come in late Saturday = more waterfalls still flowing in July.
Nearly two feet of new snow fell in the high country this past weekend. NPS road crews have plowed up to Porcupine Summit on Tioga Road. This is beyond Yosemite Creek, before the drop to the long straightaway near Porcupine Flat Campground. It's still many miles and several avalanche zones to Olmsted Point, Tenaya Lake and Tuolumne Meadows. At Glacier Point there's still so much snow it doesn't seem possible to open that area for Memorial Day weekend because water and septic systems won't be on line. It'll be a busy holiday weekend a week from now with all visitors concentrated in Yosemite Valley.

Warm then Storm

Last weekend's overcast and rain caused the Merced volume (and the tributary waterfalls) to drop back down to near average flow. One might think that rain would raise the river level, but, in fact, the cloud cover and cooler temperatures reduce the snow melting rate much more than a bit of rain can increase the runoff. Warm sun brought the flows up again through the week. Again this weekend we expect a cool storm to bring a bit of rain (and snow -which, of course, reduces the near-term runoff much more than rain does), so the waterfalls will be smaller at the start of next week than they are now.
On most days, the river (and tributary) volume exhibits a nice 24-hour cycle of rise and fall. The hottest part of the day is when the most snow melts up at 7-13,000'; this surge of melt doesn't reach the two Yosemite Valley river gauges until many hours later. It's odd that our highest water flows in the Valley happen after midnight - about 12 hours after the hottest part of the day. That's the lag time for high country runoff to make it down to 4000'.
It was cold enough in the Valley this past Tuesday morning (9 May) for people to observe frazil ice in Yosemite Creek and in Ribbon Creek. A deposit outside the eastern channel at Ribbon Creek persisted into the next day, looking like an anomalous patch of snow.
NPS road crews have reached Glacier Point, and they've reached the White Wolf area on Tioga Road, through average snow depths of 8' and 10' respectively.
The bizarre red snowplant is emerging from the ground in Yosemite Valley. Bracken fern is tall and unfolding its fiddlehead fronds. Dogwoods are fully alight now. Western Wood Pewees arrived this week in the Valley. The concentrations of yellow-rumped warblers and some other birds have dispersed from the Valley to higher elevations a bit. I've been seeing 1-2 bears a week in the Valley, more than has been my usual experience.
If you're up early and have a good eastern view, check out the concentration of planets in the east before dawn.

Tioga Road is Open

Tioga Road is not open to vehicles, but people have been traveling it all winter on skis, snowshoes and splitboards. More snow is accumulating this week, but we know it won't last long. NPS road crews have plowed from Crane Flat up to the White Wolf intersection, through an average of 7 feet of snow. Cyclists should soon be permitted to ride from Crane Flat up the highway a few miles - but be wary of administrative and maintenance traffic that may not be expecting you, and don't go beyond the marked closure points, even if you see bare pavement. Besides heavy equipment, there are avalanche dangers up here, too.
I stopped near the park's high-tech Wastewater Treatment Plant in El Portal this morning and noted four species of swallows in flight there: barn, rough-winged, cliff and violet-green. It's good to be an aerial insectivore at this time of year.