openssh unix dev - Apr 2001 - ./configure can't find zlib

I've tried to compile OpenSSH using the ./configure script, but it
always fails with the message:

checking for deflate in -lz... no
configure: error: *** zlib missing - please install first ***

Nothing I've tried has been able to tell it where zlib lives ;  I have
it installed in :

         /usr/local/zlib/lib/libz.a (and .so)     and also
         /usr/local/zlib/include/zlib.h (and zcinf.h)
on a DEC UNIX OSF/1 version 4.0 alpha machine.

I've tried the LD="/usr/local/zlib/lib" and LIBS="-lz
/usr/local/zlib/lib/libz", both before and after the ./configure. I've
also tried various combinations of those plus
--with-ldflags="-L/usr/local/zlib/lib -lz" and
--with-cflags="-I/usr/local/zlib/include", to go along with other
switches 
  ./configure --prefix=/usr/local/openssh
--with-ssl-dir=/usr/local/ssl/lib \
  --with-lastlog=/usr/var/adm/lastlog

Somehow, my understanding of the desired syntax is off - What am I doing
wrong?

                                               Thanx for any help you
can give,
                                                S. McB.