Saluda Grade in western North Carolina

[nachoman]

I assume you mean the "steepest grade in modern times"?

The Florence and Cripple Creek Railroad had a stretch of 6% and a ruling grade of 4%.

Uintah railway - <!-- m --><a class="postlink" href="http://www.youtube.com/watch?v=x7IkujWEpm8">http://www.youtube.com/watch?v=x7IkujWEpm8</a><!-- m --> had 88 foot radius curves and 7.5% grades. Of course this is narrow gauge. It was about the most treacherous non-rack railroad line that I am aware of in the USA. Sure, some logging lines were equally treacherous, but those were often more temporary tracks built quickly. The Denver & Salt lake route over Rollins pass had switchbacks and 4% grades. That line proved to be so treacherous it was bypassed with the Moffat Tunnel.