President Obama designated 346,000 acres of California’s San Gabriel Mountains as a national monument on Friday, the 13th time the president has used executive powers to establish or expand a national monument. More than 15 million people live within 90 minutes of the mountains, which are home to several rare and endangered species. The monument declaration saves the area from future development. “I can think of no better way to honor our past and protect our future than by preserving the San Gabriel Mountains,” Obama said during his designation speech. Some locals, however, say that “those environmentalists want to shut the whole mountain range down,” fearing that they “won’t stop until the mountains are off-limits to humans.” Mt. Baldy and other mountain communities east of the San Bernardino County line are excluded from the monument, a move made mainly to appease critics who feared that the monument would stunt economic growth and delay fire-safety responses.