大理石峡谷中横跨科罗拉多河的纳瓦霍桥，美国亚利桑那州北部 Marble Canyon bridges over the Colorado River at the Glen Canyon National Recreation Area in northern Arizona (© trekandshoot/Alamy)

大理石峡谷中横跨科罗拉多河的纳瓦霍桥，美国亚利桑那州北部 Marble Canyon bridges over the Colorado River at the Glen Canyon National Recreation Area in northern Arizona (© trekandshoot/Alamy)

横跨峡谷裂缝的两座桥 Bridging the gap two ways

Happy birthday, bridges

Today we're taking a trip to a part of northern Arizona cut off from the rest of the state by the Colorado River and its deep canyons. No doubt you've heard of the Grand Canyon, but today is an important milestone to another canyon about 70 miles away. On this date in 1995, the twin Marble Canyon bridges, better known collectively as Navajo Bridge, were officially dedicated as the second bridge was installed.

The first, in place since 1929 when it was hailed as a 'modern marvel' and 'the biggest news in Southwest history,' had long been key to travel across the 834-foot gap of Marble Canyon. But as time passed, the area saw heavier vehicles and more traffic. After much debate about the impact on Native land and endangered plants, and the likelihood of debris falling into the river below, plans were developed for the $14.7 million, nearly identical second bridge. Now, Marble Canyon has two bridges, each about 470 feet over the Colorado River. The original serves as a path for humans and horses while the new bridge carries vehicles. Both bridges hold the title of ninth-highest in the United States (though the newer one is about three feet higher).

生日快乐，桥

今天，我们将前往亚利桑那州北部的一个地区，那里被科罗拉多河及其深峡谷与该州的其他地区隔绝。毫无疑问，你听说过大峡谷，但今天是70英里外另一个峡谷的重要里程碑。1995年的这一天，两座大理石峡谷大桥（合称纳瓦霍桥）正式投入使用，第二座大桥也安装完毕。

自1929年被誉为“现代奇迹”和“西南历史上最大的新闻”以来，第一条铁路一直是穿越834英尺高的大理石峡谷的关键。但随着时间的推移，该地区的车辆越来越重，交通也越来越多。在对当地土地和濒危植物的影响以及碎片落入河流的可能性进行了大量辩论后，为价值1470万美元、几乎相同的第二座桥梁制定了计划。现在，大理石峡谷有两座桥，每座桥跨越科罗拉多河约470英尺。最初的桥梁是人和马的通道，而新的桥梁则承载车辆。这两座桥都是美国第九高的桥梁（尽管较新的桥高约三英尺）。