Muir fought to protect Yosemite and later Glacier Bay in Alaska, Mount Rainier in Washington and the Grand Canyon and the Petrified Forest in Arizona.

BBC: Birth and spread of the world��s national parks

This is what occurs to Henry David as he squats on the bank of Fair Haven Bay, a third of the distance from Mount Misery to the center of Concord.

NPR: Excerpt: 'Woodsburner'

Curiosity is due to turn its drill again in this mudstone for further analysis before climbing out of Yellowknife Bay and heading for the crater's big central mountain, Aeolis Mons (Mount Sharp).

BBC: Curiosity Mars rover to investigate classic rock type