Yes, GOPATH is a list of directories (like PATH). Run go help gopath for details. For example, on Linux, I have:
$ go env
GOROOT="/home/peter/go"
GOPATH="/home/peter/gopath:/home/peter/public/gopath"
$
I have something similar on Windows.
Note: Linux uses : as the GOPATH list separator; Windows uses ; as the separator.
If you use go get it will default to the first directory in the list.
Run go env to check that everything is correct.