DURING TAKEOFF THE TAILWHEEL IMPACTED A HIDDEN BOULDER, MOMENTARILY DISRUPTING DIRECTIONAL CONTROL. DURING THE COURSE OF THE PILOT'S RECOVERY ATTEMPT, HE ELECTED TO CONTINUE THE TAKEOFF. THE RIGHT WING TIP STRUCK THE GROUND, PARTIALLY SEPARATING THE AILERON. THE PILOT CONTINUED HIS FLIGHT TO THE NEAREST AIRPORT WITH APPROPRIATE EMERGENCY EQUIPMENT.