Only 2,000 people speak Lakota anymore, according to one report from the Lakota Language Consortium.
That's down from 6,000 Lakota speakers a decade ago. An effort is underway to save the language, though.
Fluent Lakota speakers like Naomi Last Horse are traveling the country and offering crash courses to beginners. Naomi was surrounded by Lakota as a child.
"It was always weaved into everything that we had done from cooking to starting a fire to having a good time," she said.
She's at the University of Denver November 18 and 19 hoping to spark a fire for learning in people like Cali Wolf, a self-described 'urban native'.
"I didn't grow up learning the language, so I felt really compelled to come out and learn as much as I can and continue that when I get home," Cali said.
She became interested in the language after moving to Denver a few years ago.
"I had a bit of an identity crisis trying to figure out who I am, and I feel like a lot of people who are urban natives feel that way," she said.
For Naomi, teaching Lakota to Cali and others like her does more than just keep a set of words alive.
"It means your identity, the color of your skin, your hair," Naomi said. "It says a lot about your customs, your traditions, your heritage, everything."
To try and get children more interested, the consortium is even offering YouTube videos of the Bernstein Bears but dubbed in Lakota: