I'm curious about why you think the Rocky Mountains would preclude this (as opposed to the distance, where ~ 500 mph via air vs. ~250 mph by train seems like a

I'm curious about why you think the Rocky Mountains would preclude this (as opposed to the distance, where ~ 500 mph via air vs. ~250 mph by train seems like a larger obstacle). Tunnels, and picking a relatively flat route seems to alleviate any concerns about the Rockies. A route roughly following the I-80 corridor would top out somewhere below 9000 ft[1]. The California high speed rail is already being designed for what I would guess are similar elevations (and perhaps steeper grades)[2]. You could also route through southern Arizona and New Mexico, completely avoiding significant mountains. 1. https://en.wikipedia.org/wiki/Interstate_80#Wyoming https://en.wikipedia.org/wiki/Interstate_80#Wyoming 2. http://articles.latimes.com/2012/nov/12/local/la-me-bullet-mountains-20121113 http://articles.latimes.com/2012/nov/12/local/la-me-bullet-m...