I want to put a public copy of half my tree up to be of use to other people (half my family wouldn't be thrilled, as I'm not acknowledged). I don't want to recreate all the work, just take out my father's side and put in all the info on my mother's--any way to copy an existing tree, so I can then do that simple manipulation?

Just download a GEDCOM of your tree- put it into your genealogy program on your computer-unlink you father from his parents- create a new GEDCOM of just you mom's side and then upload that gedcom as a new tree.

That's logical, thanks. :D

you can use familysearches free PAF geneological program. you can put your ged into it then press download and select parcial. on the next screen you can point to yor mother and select from the dropdown tab which rellies to download eg all ancestral related so filtering out those you dont want on the resulting tab. the next thing to happen is that you can see which will and wont be used in your new created ged then all you need do once happy is push download. and your original ged will still be there and the new one from your mother will be in a new file.

sounds complicated but it is very easy to do as you are guied step by step.

good luck