Finding package dependancies - Where are they?

[Ogre]

Hi,
I've installing several packages (using pkg_add) lately, and tried many more.  I generally use the pkg_add ftp://ftp.netbsd.org/(...) method, with decent success.  My problem is that I cannot always find the packages I need! For example, while installing a package listed under ftp.netbsd.org/pub/NetBSD/packages/1.6/sparc/All/, I've found that a package dependancy was in ftp.netbsd.org/pub/NetBSD/packages/1.5.3/sparc/All/!?  In another case, I could not find the dependancy in ANY of the distributions!

Am I just blind? What am I missing here? What is a good way to find where my dependancies reside, without having to search through every distro's package list? What is the logic behind the layout? I'm assuming that the packages listed for each distro just happened to be updated, or ported, during that distro's upcoming?

Very confused. Please help.

Thanks,
Reggie