“When the cantilevered structure opens to the public next month, it will be the most conspicuous commercial edifice in the canyon. And, if the tribe’s plans come to fruition, the Skywalk will be the catalyst for a 9,000-acre development, known as Grand Canyon West, that will open up a long-inaccessible 100-mile stretch of countryside along the canyon’s South Rim. The cost of the Skywalk alone will exceed $40 million.”