Exhibit 99.12

FIRST AMENDMENT TO

SHAREHOLDER AGREEMENT

This First Amendment to Shareholder Agreement (this “Amendment”) is entered on September 29, 2021 by and among the undersigned.

Recitals

A. The undersigned Shareholders are party to that certain Shareholder Agreement that became effective on June 10, 2020 (the “Shareholder Agreement”).

B. The Shareholders entered into the Shareholder Agreement to facilitate communication among the Shareholders party thereto with respect to their investment in the Company and to facilitate positive interaction and communication with its Board.

C. The Company, together with its subsidiary Altabank, entered into that certain Plan and Agreement of Merger dated May 18, 2021, with Glacier Bancorp, Inc. (“Glacier”) and its subsidiary Glacier Bank (“Merger Agreement”).

D. Pursuant to the Merger Agreement, the Company will merge into Glacier with Glacier as the surviving corporation and the Shareholders automatically becoming shareholders of Glacier common stock as more fully described therein (“Merger Transaction”).

E. In anticipation of, and effective upon the consummation of, the Merger Transaction, the Shareholders wish to amend the Shareholder Agreement in accordance with the terms and conditions set forth herein. Except as expressly set forth herein, the Shareholder Agreement shall remain in full force and effect in accordance with its terms.

Agreement

NOW THEREFORE, in consideration of the foregoing premises, and the mutual agreements set forth below, the undersigned hereby agree as follows:

1. Capitalized Terms. Capitalized terms not defined herein shall have the meaning given them in the Shareholder Agreement.

2. Designated Representatives. The Shareholder Agreement is hereby amended to the extent necessary such that the Designated Representatives shall be: (i) Dale Gunther, (ii) Blaine Gunther, (iii) Paul Gunther, (iv) Jonathan Gunther and (v) Jansen Gunther. Except as set forth herein, the provisions of the Shareholder Agreement governing the succession of Designated Representatives shall remain unchanged.

3. Shareholder Agreement Post-Merger.

(a) Effectiveness of Shareholder Agreement. The Shareholder Agreement is hereby amended as of the effective time of the Merger Transaction and to the extent necessary such that, upon the consummation of the Merger Transaction, the Shareholder Agreement shall remain in full force and effect with Glacier as the Company and the Shareholders as owners of Glacier common stock.

(b) Rule 13(d) Reporting Requirement. The Shareholder Agreement is hereby amended to acknowledge that, upon consummation of and after giving effect to the Merger Transaction, the Shareholders parties hereto will be owners of approximately 4.2% of Glacier common stock and shall therefore no longer have reporting requirements under the Exchange Act by virtue of the Shareholder Agreement.

4. Membership. The Shareholder Agreement is hereby amended to the extent necessary such that: (i) the undersigned parties to this Amendment shall each be a Shareholder under the Shareholder Agreement and benefited by and subject to its terms and conditions; and (ii) the original parties to the Shareholder Agreement that are not undersigned parties to this Amendment shall each be withdrawn from and no longer party to the Shareholder Agreement. Following the Merger Transaction, members of the Gunther family that are owners of Glacier common stock but not party to the Shareholder Agreement may become a party hereto by the mutual written agreement of such person and the undersigned Shareholders.

5. Term. Section 10 of the Shareholder Agreement is deleted in its entirety and replaced as follows: The Shareholder Agreement is hereby amended to the extent necessary such that it shall not terminate until such time that there are less than two Shareholders that are parties thereto. Any Party to the Shareholder Agreement may withdraw from and terminate its rights and obligations under thereto on seven (7) days’ prior written notice to a Designated Representative; provided, however, that such Person shall remain obligated for the payment in full of any unpaid assessment made pursuant to Section 3(d) above.

6. Further Deletions. The following sections of the Shareholder Agreement are hereby deleted in their entirety: (i) the last sentence of Section 3(a); (ii) the last sentence of Section 5; (iii) the last sentence of Section 6(c); and (iv) the penultimate sentence of Section 8.

7. Miscellaneous.

(a) Full Force and Effect. This Amendment shall be binding upon and insure to the benefit of the undersigned Shareholders. Except as specifically provided herein, the Shareholder Agreement shall remain in full force and effect. If any provision of the Shareholder Agreement is in conflict with any provision of this Amendment, this Amendment shall control.

(b) Counterparts. This Amendment may be executed in counterparts, each of which shall be deemed an original and all of which, taken together, shall constitute but one and the same instrument, which may be sufficiently evidenced by one counterpart. Counterparts may be delivered via facsimile, electronic mail (including .pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g., www.docusign.com) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes.

[signatures to follow]

IN WITNESS WHEREOF, the Parties hereto have caused this Amendment to be executed effective as of the day and year first above written.

	DRG PARTNERS, LLC

	By:	/s/ Dale O. Gunther
	Name:	Dale O. Gunther
	Title:	Manager

	THE RASPBERRY TRUST

	By:	/s/ Dale O. Gunther
	Name:	Dale O. Gunther
	Title:	Authorized Agent

	THE GUNTHER LEGACY TRUST

	By:	/s/ Orrin Porter Rockwell
	Name:	Orrin Porter Rockwell
	Title:	Trustee

	DALE O. GUNTHER

	/s/ Dale O. Gunther

	RUSSELL GUNTHER

	/s/ Russell Gunther

	JACOB GUNTHER

	/s/ Jacob Gunther

	HUDSON GUNTHER

	/s/ Hudson Gunther

	KIMBALL GUNTHER

	/s/ Kimball Gunther

	THE MARY G. MILLER REVOCABLE TRUST

	By:	/s/ Mary G. Miller
	Name:	Mary G. Miller
	Title:	Trustee

	THE BRETT AND SUSAN CHRISTIANSEN FAMILY TRUST

	By:	/s/ Brett and Susan Christiansen
	Name:	Brett and Susan Christiansen
	Title:	Trustee

	CHRISTOPHER BRETT CHRISTIANSEN

	/s/ Christopher Brett Christiansen

	P.H. GUNTHER FAMILY TRUST

	By:	/s/ Philip H. Gunther
	Name:	Philip H. Gunther
	Title:	Trustee

	BRUCE O. GUNTHER
	/s/ Bruce O. Gunther

	JULIE MARIE ROCKWELL

	/s/ Julie Marie Rockwell

	RUTH ANN GUNTHER THOMPSON

	/s/ Ruth and Gunther Thompson

	THE PAUL GUNTHER FAMILY LLC

	By:	/s/ Paul Gunther
	Name:	Paul Gunther
	Title:	Manager

	JANELLE GUNTHER

	/s/ Janelle Gunther

	JORDAN GUNTHER

	/s/ Jordan Gunther

	JENESSA GUNTHER

	/s/ Jenessa Gunther

	JILENNE GUNTHER

	/s/ Jilenne Gunther

	JUSTUS ROBERT GUNTHER

	/s/ Justus Robert Gunther

	JESSE OMEGA GUNTHER

	/s/ Jesse Omega Gunther

	JANSEN ORVILLE GUNTHER

	/s/ Jansen Orville Gunther

	JULIA KELSEY GUNTHER

	/s/ Julia Kelsey Gunther

	THE PAUL AND MIRIAM THOMAS FAMILY LLC

	By:	/s/ Miriam G. Thomas
	Name:	Miriam G. Thomas
	Title:	Trustee

	HETS LLC

	By:	/s/ Heather Thomas-Sabourin
	Name:	Heather Thomas-Sabourin
	Title:	Trustee


	GRETCHEN THOMAS PETERSON
	/s/ Gretchen Thomas Peterson

	RYAN THOMAS

	/s/ Ryan Thomas

	BLAINE C. GUNTHER INVESTMENTS, L.C.

	By:	/s/ Blaine Gunther
	Name:	Blaine Gunther
	Title:	Member

	THE BLAINE C. GUNTHER TRUST

	By:	/s/ Blaine Gunther
	Name:	Blaine Gunther
	Title:	Trustee

	THE JOHN W. HOWARD II AND KRISTIN G. HOWARD TRUST FBO HOWARD FAMILY TRUST U/A JAN. 3, 2002

	By:	/s/ Kristin G. Howard
	Name:	Kristin G. Howard
	Title:	Trustee

	KRISTIN GUNTHER HOWARD

	/s/ Kristin Gunther Howard

	THE LIVING TRUST OF JONATHAN BLAINE GUNTHER AND LISA PETERSEN GUNTHER

	By:	/s/ Jon Gunther
	Name:	Jon Gunther
	Title:	Trustee

	JONATHAN BLAINE GUNTHER

	/s/ Jonathan Blaine Gunther

	ANNE MARIE GUNTHER

	/s/ Anne Marie Gunther

	SCOTT BRINTON GUNTHER

	/s/ Scott Brinton Gunther

	GUNTHER HOLDING COMPANY LLC

	By:	/s/ Dean Gunther
	Name:	Dean Gunther
	Title:	Member

	THE GUNTHER FAMILY TRUST

	By:	/s/ Dean Gunther
	Name:	Dean Gunther
	Title:	Trustee

	SCHUMACHER FAMILY REVOCABLE TRUST

	By:	/s/ Robert J. Schumacher
	Name:	Robert J. Schumacher
	Title:	Trustee

	FIX FAMILY TRUST

	By:	/s/ Katherine G. Fix
	Name:	Katherine G. Fix
	Title:	Trustee

	KARIN GUNTHER MECHAM

	/s/ Karin Gunther Mecham

	BRIAN MECHAM

	/s/ Brian Mecham

	JILL GUNTHER

	/s/ Jill Gunther

	JST FAMILY TRUST

	By:	/s/ Shari Trexter
	Name:	Shari Trexter
	Title:	Trustee

	STEPHEN MARK HOLLEY

	/s/ Stephen Mark Holley

	BENJAMIN HOLLEY

	/s/ Benjamin Holley

	ANDREA HOLLEY

	/s/ Andrea Holley

Altabancorp SC 13D/A