X0306 4 2022-02-07 0001466593 Otter Tail Corp OTTR 0001559334 KNUTSON PAUL L 215 S CASCADE ST FERGUS FALLS MN 56537-2801 1 VP of Human Resources Common Stock 2022-02-07 4 A 0 3900 61.37 A 20147 D Common Stock 2022-02-07 4 F 0 1747 61.37 D 18400 D Restricted Stock Units 2022-02-07 4 A 0 700 0 A 2023-02-06 Common Stock 700 700 D Restricted Stock Units 2020-02-06 Common Stock 200 200 D Restricted Stock Units 2021-02-06 Common Stock 350 350 D Restricted Stock Units 2022-02-06 Common Stock 750 750 D Represents shares received upon the vesting of certain performance criteria in connection with a Performance Share Award(granted in 2019). These shares were withheld by the Corporation to pay taxes due upon vesting of this award, exempt pursuant to Rule 16b-3(e). Total direct holdings include shares acquired individually through dividend reinvestment, Employee Stock Purchase Plan and acquired pursuant to Restricted Stock Awards and Performance Award distributions. Each restricted stock unit represents a contingent right to receive one share of Otter Tail Corporation common stock. The restricted stock units vest in four equal annual installments beginning the date shown above. /s/ Paul L Knutson by Ella Leapaldt, Attorney-in-Fact 2022-02-08