Thank you very much. I apologize for the file. Thank you for amending the post.
As far as I can tell, these files are limited to Harvest Moon: A Wonderful Life (on Gamecube and PS2) and Harvest Moon: Another Wonderful Life (on Gamecube).
All files can be found on the root file of the disc (e.g. disc:\mainchapter0.arc.clz). They can be extracted by dumping an ISO of the game (e.g. using CleanRip), then can extract the ISO contents using a program such as GC Rebuilder.
On the PS2 version of the game, it seems that there is both a compressed (mainchapter0.arc.clz) and uncompressed (mainchapter0.arc) version of the same file, although these might have issues due to the PS2 using little endian (as opposed to big endian on the gamecube).
These files can be found by opening the PS2 ISO of the game, then opening DATA0000.AFS using AFS Explorer.
Samples of these files (from any version of the game) can be provided upon request.
I'm unsure whether it would break the Terms of Service to upload/link the files here, but I do have some info about my work researching the files on my WordPress blog for the project.
I'll do some more digging into variants of the LZ77 and LZW (I believe some other games around that time also used LZSS).
There are also European and German versions of the game, but I haven't done much work on those versions. Once I've been able to modify files on the English (USA) versions, I should be able to use that same knowledge to create a romhack of the German version (although I will likely need some help with translating).