How much is my stock worth?

My grandmother passed away several months ago and left everything to me. I just discovered that she had a second lock box at another bank and when I went to retrieve its contents I found documents indicating that she had 10,142 shares of the bank that my grandfather used to be president of back in the 70's. I was wondering how I could find out how much each share is worth. Should I call my stock broker or just call the bank? or is there anywhere that I could find it online? Thanks in advance!