Mountains, Precipitation and Rivers

[davoush]

Hello,

I just have a quick question about river placement which some of the more knowledgable in that department might be able to help with. Basically, I have a large north-south mountain range (spanning approx 30 to -30 latitude) that sites on an eastern coast. Would it be unreasonable for one (or two) large rivers to flow from the rain-shadow side of the mountain down through the desert? Or would they only be likely to form on the coastal side of the mountain?

Thanks.

[kirkspencer]

Sort of. Example from reality: the North and South Platte rivers are primarily snowmelt driven from the rain-shadow side of the Rocky mountains of the US, and join in Nebraska to form the Platte river. It's "a mile wide and six inches deep" - even during the spring run-off it was (even before diversions) too shallow to be considered as reliable transport even for canoes.

Note the Platte is a major tributary for the Missouri river, which supported riverboat traffic from St Louis Missouri to Fort Benton Montana - a nominal 1450 miles. And the Missouri also originates in that 'rain shadow' eastern side of the Rocky mountains.

There are more details, of course, and reasons the Missouri is deeper and stronger than the Platte, but that's two rivers flowing from the rain-shadow.

[Redrobes]

You can have a read through a big thread about river placement here:
https://www.cartographersguild.com/s...ead.php?t=3822

Hard to answer your question exactly but I think it might depend whether the tops of the mountain had significant snowfall. I am fairly sure you would get some rivers forming but they may go into the sea or may go into a dry desert area and evaporate. It would depend on a number of factors. Because you have a long range of 60 degrees then its also likely that different outcomes would occur in different lattitudes too.