I downloaded the Halo Demo on the mac, and im wondering if there are any Zelda themed maps i can use in the place of Bloodgulch. I was really looking for one of the Ocarina of Time Hyrule Field, but any Zelda would be nice.

It has to work with Halo 1. I know there are Halo 2 Zelda maps, but would they work with Halo 1?

If you plan on doing ANY map replacements. Back up a file of the old map to begin with. But to answer your question, no one here makes these kinds of maps for halo 1 I don't believe. I have seen weapon, particle, and texture mods for halo 1 maps, but I think that may be the extent to what people can do. I am unsure on this though but replacing a map with a completely different map is VERY unwise unless every single person has that same map replacement.

I do have some maps for Halo 1, that are COMPLETELY new, and original. Im not worried about backing up maps, i have like 8 copies of the original bloodgulch, along with all of the other maps i have. Im just wondering if anyone has a mod that is Zelda related, because i know some people make full mods like that.

Is there any chance that the Halo 2 maps are backwards compatible, or that there is a program to open halo 2 maps and convert them to Halo 1 format?

That be a definite no actually.
BTW the definition of backwards compatible means the OLDER is compatible with the NEWER, not the other way around.

Bleh, i meant forwards-compatible.

Anyways, im going to look into those programs.

There are custom edition maps based off Zelda.

there are some for custom edition, but not standard halo. The Custom Edition one is of almost all of Ocarina of Time's outside of dungeon area.