In Mexico, a quest for autonomy.(Chicago Tribune)

YALALAG, Mexico _ High in the Juarez Mountains of southern Mexico, life finally is changing for the better for the Zapoteca people who have grown corn and squash on the mountain slopes for a thousand years.

A pipe run from a high mountain stream now brings clean running water to the town's tile-roofed adobe homes. The rebuilt City Hall, painted a brilliant green, features the town's first dental clinic and library. Receiver towers bring television and phone service to Yalalag. Dogs are vaccinated against rabies, and many people recycle trash.

"We've worked a lot here over the years to build this," said Nereo Tizo, who works at a bank of public phone booths along the town's single main street, traversed by pack-laden burros. "Before there were no services here, no progress."

But as the Zapotecas of Yalalag are finding out, winning real progress for Mexico's more than 11 million indigenous citizens is a precarious process.

In April, Congress approved long-sought constitutional reforms designed to give Mexico's 62 indigenous groups new constitutional rights and an official measure of autonomy to run their own affairs. The reforms, pushed through as a precondition to peace with …