X0306 4 2020-08-20 0 0001402829 Orion Group Holdings Inc ORN 0001417119 Stauffer Mark R. 12000 AEROSPACE AVENUE SUITE 300 HOUSTON TX 77034 0 1 0 0 Chief Executive Officer Common Stock 2020-08-20 4 A 0 168750 A 734926 D Common Stock 2020-08-20 4 F 0 31515 3.13 D 703411 D Represents the number of shares earned under a performance award granted on May 24, 2019. One half of the shares vested on August 20, 2020, with the remaining half vesting in two equal installments on August 20, 2021 and August 20, 2022, subject to the Reporting Person's continued employment through the applicable vesting date. Reflects a reduction of shares of performance-based stock withheld to cover taxes payable by the Reporting Person due to the vesting of shares on August 20, 2020. Mark R. Stauffer 2020-08-24