For the last two weeks in February, this small waterfall in Yosemite Valley gets illuminated at sunset by the sun's final rays. This isn't the best example but it's the best I've taken so far. The best cases cause the water to appear to be falling embers. The best image thus far has been captured by Galen Rowell.

You can see different phases of color over a short period of time in my gallery. Hit Next a couple of times to see a total of 4 different images of the falls.