Fist City Puns

So my dad and are touring a college in Rapid City, South Dakota, and we drove past a Geology Museum. He casually pointed it out as we had not noticed it before. I waited a few seconds, fully expecting a Geology rocks joke, but he was silent. I asked him why he didn't make a joke, as he is notorious for awesome dad jokes, and he looked at me and said, "I was going to but I felt like I was stuck between a rock and a hard place." I just looked at him and gave him a fist bump. This is going to be a great trip.