I like the split rail too, it is very rustic, but it doesnt look very Colorado-ish to me: First of all the species of cedar that can be split into rails are not common in Colorado, the common species that could be split such as Ponderosa and douglas fir tend to have too many knots to split well, and would not last long outdoors in Colorado. Also, since most of the ground in the Rockies is well, rocky, many Colorado fences were built of unsplit rounds using the zig-zag style like this:
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images.google.com]
Also, to me the fence as built is somewhat of a safety hazard, toddlers and kids can crawl right through the fence towards the train, while parents would be blocked..