Upload & Sell: On
Since I correspond with a number of folks, I can offer second-hand reports about some developments in the Sierra, along with my first hand report from the five days including this past weekend.
I have heard from two sources that some aspens are changing color in the Sonora Pass area. The description referred to starting to change, and (no surprise) not to anything like in full color.
I have heard from a few sources who have been up there that there is some color starting in the Bishop Creek drainage, including a (very) few trees that are apparently quite colorful.
My own recent visit was between 9/12 and 9/16. I was in the Tuolumne area for the first two days, though I did make a quick visit to Lee Vining Canyon. Inside the park, the usual high country non-aspen signs of on-coming fall are present - golden brown meadows, corn lilies turning brown and falling over, color coming to willows and bilberry and other plants. But I saw no aspen color inside the park. There might be a bit in a few spots - since I certainly didn't see the whole park! - but nothing remarkable. Again, no surprise in mid-September. (Yosemite itself is not exactly a hotbed of aspen color. You can find it, but most look to the east side of the range.)
Over Tioga Pass I saw more of the non-aspen color, and a bit of color coming to aspens between Ellery Lake and the big rock slide area on highway 120 - for example, in the area of the big right hand bend (descending) before the road heads down to Lee Vining Canyon. I'd classify this more as "hints of color" than as "color to drive 200 miles for." ;-)
In Lee Vining Canyon there was a tiny bit of color, but the trees were almost completely still green. I saw a few trees that perhaps had a few yellow leaves or even a single yellow branch, but that doesn't usually mean much. (Lee Vining Canyon is often a place that changes a bit later, and a good place to look for color after some of the higher areas are spent.)
On Sunday, driving back from McGee Canyon on 395, I tried to squint into the western sun to see if I could spot anything going on up on Parker Bench and the surrounding area, but it anything is happening up there, I couldn't see it. (Later in the season, you can most certainly spot the beautiful color up there from 395.)
I was on the trail up McGee Canyon on Friday 9/14 through Sunday 9/ 16. I expected little or no aspen color in this relatively low elevation valley where I have photographed aspen color two or three-plus weeks later in a typical season. I was surprised to find that some of the large groves a mile or two up the canyon, after it bends to the left, were starting to show color. A few trees were perhaps 1/4 or 1/3 yellow, many had a few yellow leaves, one (!) had some orange leaves... but there was still a lot of green. If I had felt like it, I there were a few trees where I might have taken my pack off and found an aspen color photo - but overall it is still too early.
However, as I mentioned earlier, it sure seems like things might be getting going a bit early this year. I typically expect to find good color in the eastern Sierra sometime during or near the end of the first week of October. (You can find it a bit earlier in some odd, higher spots.) Often the color remains good, if you know where to look, right on into the middle of the month, and it is possible to find good color at lower elevations even a bit later - though this can be effected by the weather the later you wait. I'm pretty conservative about believing reports that interpret a few early colorful leaves as an indication of an early season - most of them seem to start about the same time no matter what. But, for what its worth, I'm betting that things will come along a bit earlier in the Sierra this year. I'll probably be back before the month ends, and normally would not go that early.
Though I may have to eat my words... ;-)
(If you want to know more in general about eastern Sierra aspen photography, there is a post at my blog with some info and links to even more stuff: http://www.gdanmitchell.com/2009/09/02/sierra-nevada-fall-color-season-coming-sooner-than-you-think )