Maybe you are not adding to the path but overriding it?
Could you post the corresponding lines in csh.cshrc.local please? Or maybe even the whole file.
Something like this should work to add directories to the path:
set path = ($path /usr/local/bin)
(taken from http://www.cyberciti.biz/faq/unix-linux-set-path-variable-in-c-shell/ and I tried it too, ls still works with that in /etc/csh.cshrc.local… 
)