Michelle Obama surprised students of the Gila River Indian Community on Tuesday.

The former first lady joined Gila River Gov. Stephen Roe Lewis, who already was meeting with the students at the Huhugam Heritage Center on the reservation. The select handful of students was sitting around a table when the governor grinned and appeared shocked as Obama entered the room.

Obama was in Phoenix for a stop on her book tour.

She met with the students to hear their stories about life on the Gila River Reservation south of Phoenix.

In response, the students began speaking one by one about their current level of education, plans and challenges they face.

One student shared her experience with adapting to a college environment, which lacked the same cultural support system she experienced in Native American schools.

Obama acknowledged the challenge.

"Being the only one is hard, and it takes a toll on you in a way that the majorities don't understand," she said. "A lot of these schools and universities don't understand that it's important to make sure that you're not just admitting the one or the two (students). You have to bring kids in in groups."

Obama complimented another student on how poised she was.

"I'm so proud of you," Obama said. "I'm so proud of you all, my gosh."

In continuing to push the initiative Reach Higher, Obama aims to inspire every student in America to complete their education beyond high school in order to receive a two- or four-year degree, a certificate or a credential.

Reach Higher is partnering with Yoobi, a school-supply company, to donate school supplies to the 900 elementary- and middle-school students in the Gila River Indian Community.

Michelle Obama was accompanied by Valerie Jarrett, a long-time aide to President Barack Obama.