"A 1,904-square-mile natural wonder in Arizona that has positioned sustainability at the core of its visitor experience. The park pairs dramatic vistas and historic traditions with eco-conscious operations: a vintage rail link shuttles guests to the South Rim in restored cars while musicians add Old West atmosphere, park kitchens divert unsightly produce to mule feed through Operation Shrivelly Apples, and mule manure is composted at scale. These efforts have included feeding over 76,000 pounds of recycled food scraps to the animals since 2013 and composting more than 700 tons of mule manure annually. Multiple on‑site restaurants hold top Certified Green Restaurant ratings and the park works with operators to measure and reduce energy, water and food use, minimize waste, and source sustainably." - Emily Hochberg