Yes they still exist and yes still alive, after surviving imperialism and genocide. Many were forced to attend boarding schools, which the U.S. government used as a way to assimilate native children (lose their language, culture, traditions). They've endured historical trauma. I recommend reading books on this, because there is much to talk about.
There are many indigenous peoples in Arizona, California and so many other states. There are a lot of tribal nations and pueblos if your from New Mexico. many Natives are fighting to reclaim their language and protecting their ancestral lands.
There are about 5 million Native Americans in the US, according to the 2010 US Census. Of those, about 3 million consider themselves to be solely Native American; and 2 million describe themselves as being of mixed race. Of those 5 million, about one million live on reservations, and other four million live in among the rest of the US population.
Many reservations are on poor land in remote places, and economic opportunities are often extremely limited. Many Native Americans leave their reservations for a few months or years to work, and then move back to the reservation for as long as they can.
One way to learn more might be through movies and books. I recommend the movie "Smoke Signals" (Chris Eyre, 1998); the PBS TV movies "Skinwalkers," "Coyote Waits," and "A Thief of Time;" and the current Netflix series "Longmire;" and books by Louise Erdrich and Sherman Alexie.
(@Neil - What you say is true. But it is not relevant.)
I've been always curious about Indians (Native Americans), and I started a discussion
about them once, but it didn't get many responses, here it's if you like to check it:
https://www.italki.com/discussion/89210
Also you could check these links:
https://en.wikipedia.org/wiki/Navajo
