IMO, and I could be wrong, but the drive from Minn/St Paul, other than the Mall of America in Minneapolis, has nothing of interest until you get to the Badlands, Custer STate Park, Crazy HOrse, Mt Rushmore area. Deadwood SD for a day and night, I found to be of interest.
Sinoatrial node is located at the junction of the superior vena cava with the right atrium.
The entire heart muscle has the ability to conduct electricity. The sinoatrial (SA) node acts as the primary pacemaker of the heart. It sends signals from the top chambers to the bottom chambers throughout a persons lifetime. The usual heartrate is 60-100 bpm with normal activities. The atrioventricular node (AV) acts as a governor for the signals coming from the top chambers and it conveys these signals down to the appropiate bottom chambers (ventricles). Sometimes the primary pacemaker (SA node), becomes too slow and the AV node may have to take over the rhythm. This is known as sick sinus syndrome, and depending on the circumstances, may require an artificial pacemaker. So in summary, yes, there are two natural pacemakers the SA node and the AV node.