After some initial trouble with the More Height Levels (MHL) patch, the mountains should now be glitch-free, so they are safe to conqueror by train, road vehicle, aircraft, and even by ship!
There are other features and fixes too, for the full log, see the [url=http://binaries.openttd.org/releases/1.5.0-beta2/changelog.txt]changelog[/url]. If you are more interested in playing, [url=http://www.openttd.org/en/download-testing]download here[/url].

The new beta is just perfect for checking out the save-games of the title game competition, after [url=http://www.tt-forums.net/viewtopic.php?p=1143165#p1143165]looking at the screenshots and sending in your votes[/url].

Have fun climbing the mountains,

The OpenTTD team