Rg7#
can anyone help me find a mate?

Whew! At first I misinterpreted the title!
Yup, 22.Rg7 was checkmate. Good game and congratulations on your (late) victory!

Even before move 22 you had mate in 2:
20. Ne6+ Kg8 21. Rg7++.
Always examine all checks when conducting an attack.

Also you couldv'e have won a rook on move twenty with that pin you had on the king.
20. Rc7 Ke8 21. Rxc8 Kd7 22. Rxh8 Kxd6

Even before move 22 you had mate in 2:
20. Ne6+ Kg8 21. Rg7++.
Always examine all checks when conducting an attack.
20. Ne6? Bxe6
Right?
so simple, thanks everyone. RGrizzard, I avoided 20. Ne6 because I thought ...Bxne6 21. Rxe6 + and I wanted to hold onto my horse for the time being.
I only moved there on 21 because of the bishop pin. That makes 22. Rg7++ a perfect forced check without all that clumsy rook trolling. 28. Rc8++ also makes a lot of sense.
I just played this game and was annoyed because I knew a mate existed but was only able to find it after some time. Can anyone spot an earlier mate for white, or black, in this game for me?