X0306 4 2016-04-08 0 0001466593 Otter Tail Corp OTTR 0001278053 MACFARLANE CHARLES S 215 S CASCADE ST FERGUS FALLS MN 56537-2801 0 1 0 0 President & COO Common Stock 2016-04-08 4 F 0 994 28.415 D 90436.0491 D Common Stock 2320.9596 I ESOP Common Stock 1829.4631 I by daughter Common Stock 1829.4631 I by son Common Stock 2016-02-06 Common Stock 6000 6000 D Common Stock 2017-02-06 Common Stock 9500 9500 D Grant of Restricted Stock. On 4/8/2016, 994 shares of Common Stock were withheld by the Corporation to pay taxes due upon vesting of restricted stock, exempt pursuant to Rule 16b-3(e). Total direct holdings include shares acquired through the Dividend Reinvestment Plan, the Employee Stock Purchase Plan and shares acquired pursuant to Stock Options, Restricted Stock Awards, Restricted Stock Units and Performance Share Awards. 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 February 6, 2016. The restricted stock units vest in four equal annual installments beginning February 6, 2017. /s/Charles S MacFarlane by Ella Leapaldt, Attorney-in-Fact 2016-04-11