In junior high school, Thomas conceived and implemented a program to preserve the fragile Rio Grande ecosystem by wrapping chicken wire around threatened cottonwood trees to protect them from beavers. The program replaced a policy of killing the animals to save the trees. Initially told by wildlife officials that there was no funding available to try his idea, Thomas solicited donations of materials from local businesses and got his school and community to help him wrap the trees. He used the publicity generated by his success to raise awareness about the plight of the river, whose ecosystem is heavily impacted by diversion of its flows for human use. The Rio Grande was listed as one of the ten most endangered rivers in the country. Thomas served on the mayor’s Aquifer Youth Corps and as a River Ranger, continuing his educational work even as his tree-wrapping program expanded to new areas of beaver habitat along the Rio Grande.