A desert would most likely form on the leeward side of a mountain. would it most likely form at the top or at the bottom of the leeward side?

Which would be least likely to get rain as the clouds pass over the mountain? Depending on the height of the mountains, there might be some residual rain coming over the top of the mountain.

However, since this is not my area of expertise, I searched Google under the key words "rainfall mountains desert" to get these possible sources:

http://en.wikipedia.org/wiki/Rain_shadow

After this, I searched under "rain shadow."

http://bcs.whfreeman.com/thelifewire/content/chp56/5602001.html
http://www.weatherpages.com/rainshadow/
http://animals.about.com/od/alpinemontaine/f/rainshadow.htm
http://pubs.usgs.gov/gip/deserts/types/
http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/precipitation/rain_shadow.html

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

I hope this helps. Thanks for asking.

A desert would most likely form at the bottom of the leeward side of a mountain. Let me explain the reason behind this phenomenon.

When air encounters a mountain, it is forced to rise. As the air rises, it cools and forms clouds, leading to precipitation on the windward side of the mountain. This process is known as orographic lifting.

On the leeward side of the mountain, the air starts descending. As the air descends, it warms up. This process is known as the rain shadow effect. Warm air has the ability to hold more moisture, so as it descends, it becomes dryer and less likely to sustain clouds or produce precipitation.

The descending air of the leeward side is associated with dry, stable atmospheric conditions. This leads to a decrease in rainfall and a higher likelihood of aridity, making it conducive for the formation of deserts.

Therefore, deserts are more likely to form at the bottom of the leeward side of a mountain due to the rain shadow effect.