PITTSBURGH — A sixth grade class at Center Avenue Elementary School is one of three winners in the Pittsburgh Zoo & PPG Aquarium's Go Green contest.

Each winning school will receive a free zoo class at their school and the opportunity to display their projects at the zoo on World Environment Day, June 5.

The zoo challenged elementary schools in Western Pennsylvania to design projects that would encourage schools to incorporate conservation measures to help clean up the environment.

The schools chose from one of three categories: Green Tree Frog Award, Silverback Award, and Polar Bear Award.

Barbara Frantz's sixth grade class won in the Green Tree Frog category, which had the challenge to design and plant a garden, to plant native trees at the school or to raise money for Arbor Day.

The Center Avenue students formed a new after school garden club. They researched native trees and plants, and planted trees on the playground. They submitted details of the project before and after plantings on the playground.

Center Avenue Elementary is in the Butler School District.