Free: Contests & Raffles.
Bears are flat out tougher than any other animal when it comes to death. They don't stop until biology says they have to if they were spooked at the shot. You'll find it within 300 yards of where you lose the blood trail is my prediction; thye just can't run much farther than that once they are out of blood. You may get lucky and find it got woozy and ran into a tree and couldn't get up not far from where you stopped. Head on shots are tough to gauge longevity by; too high and you get one lung, too low and you get bottom of heart; both can bleed well but not immediate death shots. Left or right are poor penetration, and that sounds like your case from your broken arrow description, and those generally only get part of one lung, which means a long run.Go back in at daylight and find him. From your description you were close and probably bumping him. If that's the case, then coming out tonight was a good thing because he'll calm down and get sick and lay down and never get up again.