it is called la pampa. this is not just environmental disaster.l question of national and international security. the peruvian government declared a state of emergency here which is still in effect. and launched operation mercury three years ago. they successfully pushed 25,000 miners out of la pampa. despite it all, they are hopeful. they made strides in their reforestation work, figuring out what can be replanted. the largest such enterprise in the americas. that's a beauty. >> this is caliandra. it's a survivor. this was all desert a few years ago. but with their help, and a little push from mother nature, it's coming back. >> nature always heals itself. it depends on how long it takes. >> if we don't mess it up too much. >> talking to a biologist, nature scales on the scale of asteroids killing dinosaurs. >> reporter: realizing the amazon doesn't have that kind of time, the battle to save it continues as the destruction rages on. cynthia mcfadden, nbc news, la pampa, peru. >>> up next, savannah guthrie's exclusive with tennis great roger feder

so la pampa is an area next to the highway. about 5 years ago, this was a place that was a couple miners, a couple tents. and it eventually became an illegal city that had thousands of people and was the gateway to the hotspot of illegal gold mining in the amazon. [karina garay speaking spanish] fernandez: it's a place that has now been taken apart by a government action called operation mercury. [man yells, men respond] [garay speaking spanish] [garay speaking spanish] [garay speaking spanish] [gonzalo cordova speaks spanish] [garay speaking spanish] [woman speaking spanish] [camera focus adjusting] [garay speaking spanish] [garay speaking spanish] [luis loraico speaking spanish] [garay speaking spanish] [woman speaking spanish] [garay speaking spanish] [garay speaking spanish] [luis loraico speaking spanish] [garay speaking spanish] [luis hidalgo okimura speaking spanish] [teacher speaking spanish] fernandez: an ngo that tracks mercury a mining has estimated 185 tons of mercury are released to the rivers and lakes of this reg