I was playing a 3 person scramble at Osage National on Sunday 3-18-18. It was a cool 50 degree day and overcast. We came to the Par 3 7th on the River Course. The yardage showed 142 from the tee box. I had a PW in hand and decided to grab a 9 iron due to the fact the air was pretty thick. The hole was cut on the back left of the green. I hit a nice baby draw onto the green and the ball bounced once and started tracking to the hole and then disappeared. There was another group playing with us as well, and everyone just went nuts. It was the first Hole-In-One everyone in the group had seen in real life. I actually had 5 witnesses.