Giant sequoias, long viewed as majestic, impervious guardians of the high Sierra, are beginning to struggle with the multi-year stretches of drought, according to research conducted in Sequoia and Kings Canyon national parks and elsewhere in the Sierra.

Such a pitiful throw. I watched my boot wobble above Mono Creek, then— in what seemed like real-life slow-mo—bounce against a rock and flip into the rushing current. Gone, gone, gone. Barefoot on the bank, I screamed, cursing my idiocy for tossing my boots instead of carrying them across in the wading shoes lent by my new friend, Doug Crispin. My life flashed before my eyes there on Mono Creek, days from anywhere. But then, someone was crashing through the creekside foliage.

For the second day in a row Thursday a massive slab of rock peeled from the face of El Capitan and fell to the floor of the Yosemite Valley. This rockfall, though larger than the one Wednesday that killed a British citizen, resulted in no fatalities but did injure one, Yosemite National Park officials said.