Simplify the following text for a Grade 15 native English-speaking person.
Original: Ansel Easton Adams ( February 20 , 1902 â `` April 22 , 1984 ) was a legendary American photographer and environmentalist , best known for his black-and-white photographs of the American West and primarily Yosemite National Park .
Simplified: Ansel Easton Adams ( February 20 , 1902 â `` April 22 , 1984 ) was an American photographer and environmentalist , best known for his black-and-white photographs of the American West , especially in Yosemite National Park .