Getting the bark off while the wood is fresh will be your key. Do not wait but about 3 quick eyeblinks before you slap on some polyurethane, latex paint, wood glue, shellac, or something to seal the back and the ends, mind you! That will stop the wood from getting cracks/checks.
Like another said, once you have allowed the wood to cure a few months, you can reduce it closer to bow dimensions and bring it indoors or place it where there is more air movement and even sunshine to help cure it out a little faster. You may get a little warping or twisting, but hickory will accept treatment from a heatgun and you can undo all that nonsense when the time comes!
We'll walk you through it and see you taken care of! Just pay back the debt by passing on your experience and talents to someone else, that's how we all got to where we are now!