Posted by H3ADHUn73R>An official assault map or militia map has not been released by valve yet. So far, any maps not officially released by valve with the source launch are considered "illegal", and steam will not download them. You have to download them by hand. Now, valve won't actaully go after you for playing these anymore, since the SDK is not out, everyone can make maps. So, download them from this site, and then go head and play them.
actually for quite some time user made maps have not been "illegal" because the SDK was released and after the SDK was updated when HL2DM was released they enabled auto downloading of maps
and for assault... get zt_assault it's the best one