Can I dump/bury cat waste in woods?

I have 2 cats and every week when it is time to change the litter box I feel guilty for using a plastic liner and put the waste (which by itself is totally biodegradable and completely breaks down in few days or weeks) in a bag which will probably stay in the landfills for ever. So I looked around and found a brand of liner which is supposedly biodegradable but I still don't feel right about this because I am sure that it will still take a long time for the waste to break down. So I am wondering if environmentally it is better if I dump the waste in the woods at the end of my street and if it is legally ok to do so(I live in suburbs of St. Paul, Minnesota, US)?