X0306 4 2023-02-25 0 0001037676 ARCH RESOURCES, INC. ARCH 0001809723 Giljum Matthew C. ONE CITYPLACE DRIVE SUITE 300 ST. LOUIS MO 63141 0 1 0 0 Sr. VP and CFO Common Stock 2023-02-25 4 M 0 3733 A 15969 D Common Stock 2023-02-27 4 F 0 1654 152.62 D 14315 D Common Stock 2023-02-27 4 M 0 3387 A 17702 D Common Stock 2023-02-27 4 A 0 19049 A 36751 D Common Stock 2023-02-27 4 F 0 9941 152.62 D 26810 D Common Stock 2023-02-27 4 S 0 573 148.05 D 26237 D Common Stock 2023-02-27 4 S 0 200 149.77 D 26037 D Common Stock 2023-02-27 4 S 0 200 150.78 D 25837 D Common Stock 2023-02-27 4 S 0 300 152.15 D 25537 D Common Stock 2023-02-27 4 S 0 1144 153.18 D 24393 D Common Stock 2023-02-27 4 S 0 200 153.58 D 24193 D Restricted Stock Units 2023-02-25 4 M 0 3733 0.00 D Class A Common Stock 3733 3734 D Restricted Stock Units 2023-02-27 4 M 0 3387 0.00 D Class A Common Stock 3387 0 D Each restricted stock unit represents a contingent right to receive one share of Class A Common Stock of Arch Resources, Inc. (the "Company"). These shares were withheld by the Company to satisfy the reporting person's tax withholding obligations. Represents an award of Performance Stock Units originally granted to the reporting person on February 27, 2020. On February 9, 2023, the Issuer's Board of Directors determined that the performance conditions with respect to such award had been satisfied, resulting in the vesting of the shares of Common Stock reported herein. The sales of shares was pursuant to the reporting person's pre-existing Rule 10b5-1 trading plan and represents an automatic sale to cover tax obligations and for other purposes. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $147.57 to $148.21 per share. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $149.36 to $150.18 per share. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $150.43 to $151.12 per share. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $151.58 to $152.54 per share. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $152.58 to $153.57 per share. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The restricted stock units are fully vested. /s/ Rosemary L. Klein, Attorney-in-Fact 2023-02-28