By Shannon Urtnowski
NBC News associate producer

In conjunction with NBCUniversal's Green Week, Nightly News will bring you a special report tonight about two youths with a big dream and tough legs.

Through their non-profit organization Pick Up America, Jeff Chen and Davey Rogner have been traveling across the country picking up litter and spreading a message of zero waste.

Since March 2010, Chen and Rogner have walked almost 2,000 miles and gathered more than 140,000 pounds of trash along the way.

But the two don't work alone. They have recruited various volunteers along the way, some for just a day and others for months at a time.

Chen and Rogner say they want Pick Up America to instill lasting change in behavior and mentality among the individuals they touch.

"I'm hoping that we can create this kind of respect for the earth," Chen said. "And I think it's very much up to us youth to do that."

Pick Up America has completed half its journey to date. The team, currently just outside Denver, started the pickup in Maryland and has San Francisco in its sights.

The journey is supposed to end there in one year. But Chen and Rogner hope the message will last a lifetime.

Watch the full report Wednesday at 6:30 ET on Nightly News with Brian Williams.