{"id":9667,"date":"2011-11-20T09:06:40","date_gmt":"2011-11-20T14:06:40","guid":{"rendered":"http:\/\/www.howderfamily.com\/blog\/?p=9667"},"modified":"2022-05-17T18:06:07","modified_gmt":"2022-05-17T23:06:07","slug":"subterranean-continental-divide","status":"publish","type":"post","link":"https:\/\/www.howderfamily.com\/blog\/subterranean-continental-divide\/","title":{"rendered":"Subterranean Continental Divide"},"content":{"rendered":"\n

I have a fascination with tunnels. So I like to feature them regularly, including articles such as Superlative Tunnels<\/a>, Tunnel Under the Border<\/a>, and Tunnels, Bridges, Lifts and Inclines<\/a>. Also I’ve fixated on boundaries and watersheds such as the Hydrological Apex<\/a> of North America.<\/p>\n\n\n\n

It seems odd to me that I hadn’t yet encountered a mashup of the two. Yet that’s exactly what occurred when I read an article<\/a> in Slate a few weeks ago. The article wasn’t about tunnels or watersheds precisely. Rather it focused on traffic efficiency versus driving speeds. It featured the counterintuitive notion that “sometimes you have to go slower to go faster.”<\/p>\n\n\n\n

Colorado throttles Interstate 70 speeds down to 55 miles per hour west of Denver at certain levels of congestion. They do this by using police cars as rolling roadblocks. It’s an interesting concept. You can read the article on your own if you prefer because it’s not actually germane to this conversation. I latched onto a single phrase… “a two-mile-long tunnel that dips under the Continental Divide.<\/em>“<\/p>\n\n\n\n

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Eisenhower Tunnel<\/h2>\n\n\n\n
\"Entrance,<\/a><\/figure>\n\n\n\n

You read that correctly. It’s possible to drive across North America’s continental divide below the surface. Technically this is the Great Divide, one of several “continental divides”. However it’s the most well-known version and generally the one that’s meant when someone mentions a divide without qualifiers. It’s pretty cool even with the asterisk, don’t you think?<\/p>\n\n\n\n

It required a little fact-checking because it sounded almost too good to be true. The Colorado Department of Transportation certainly believes it. They constructed the Eisenhower Tunnel<\/a> in two phases in the 1970’s, the Eisenhower Memorial Bore for westbound traffic and the Edwin C. Johnson Memorial Bore for eastbound traffic. CDOT throws out a number of superlatives as they describe their engineering achievement:<\/p>\n\n\n\n

“It is the highest vehicular tunnel in the world, located at an elevation of 11,013 feet at the East Portal and 11,158 feet at the West Portal. The Tunnel traverses through the Continental Divide at an average elevation of 11,112 feet… Annual snow fall in the area averages 315 inches (26 feet) for the months of November through April.”<\/p><\/blockquote>\n\n\n\n