I think you can but I wouldn't advise it as it won't line up well.

Maya is mainly used to create models for your level, not to create a level itself.
MESA and the prall scripts manage to import the dXF exported from hammer, but the the version 2011 to 2013/2014 will give you a wrong scaling when imported in maya.
the plugin to from Valve will also import a structure of brush, but will not be useful to imported to modified model you made in maya.
it can be useful if you must absolutely respect the scale. like if you create a wall that will explode in your map. so you export in dxf to maya, and you base the proportion on the
but in any manner you will have to create your level in maya. - > hammer ;)

Red

thank you so much, i'll have to go through all the terminology and do my research, but i greatly appreciate your comments... i know it will set me in the right direction. Thank you!

I am new to the Steam Forums and i understand there is a vast community of developers,
i am working on a few project directed towards valve, do you know if there is a list i can access to usernames of people who develop different elements for games that i can access,
this is so that we can share our idea and see if people want to work together on a project that open for community development.

any suggestions to set me toward that direction is much appreciated since i am a designer and am learning source sdk along side maya and other game engines...