The great Rocky Mountain landscapes are a treasure for the world. In them, I see what we in Europe have lost. I don't want that to happen here. — Florian Schulz, photographer

This is North America's great and wild heart, and the challenge of the modern era is to keep it from breaking. — Douglas H. Chadwick, wildlife biologist

Stretching nearly 2,000 miles through North America's wild heart, the Yellowstone to Yukon region is one of the world's last fully functioning mountain ecosystems.

Due to encroaching development, this sweep of wilderness is in danger of being broken up. National Parks are becoming islands of wildlife protection. They are no longer adequate to ensure the health of their wild inhabitants: the region's mammals need connecting corridors that allow them the freedom to roam between protected areas.

Driven to help save true wilderness, German photographer Florian Schulz spent ten years photographing the Yellowstone to Yukon region. His images complement one of North America's largest and most urgent conservation efforts. The Yellowstone to Yukon Conservation Initiative is an organization dedicated to restoring and maintaining the largest remaining wildlife corridor in North America.