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J. Walter Sinclair

Of Counsel

800 W. Main Street, Suite 1750, Boise, ID 83702

Walt Sinclair provides clients the perspective of an experienced trial lawyer in a wide range of complex disputes. 

Walt has extensive bench and jury trial experience, having handled 30 jury trials and 11 bench trials. Walt utilizes cutting edge technology to be the most cost efficient and effective as possible in representing his clients. In the last decade, Walt has focused his practice primarily on the federal courts, with extensive trial time in the U.S. District Court of Idaho. He has also worked closely with the Court as a Federal Representative to the Federal Court for the District of Idaho, an officer of the Idaho Legal History Society, and a member (and president 2016 & 2017) of the Idaho Chapter of the Federal Bar (which awarded him the Exemplary Service Award in 2013).


Seasoned Trial Attorney

In practice since 1978, Walt has developed a proficient trial practice in both state and federal courts with an emphasis on business, corporate, and complex litigation matters associated with agricultural product liability, complex commercial contract disputes, insurance coverage, mass tort, probate disputes, product liability, and real estate litigation.

Client Results

  • Walt’s approach to litigation is the “team” approach, where he applies his experience and expertise in evaluating and strategizing a case, while working with associates and paralegals to get the work done most efficiently. He has addressed multiple types of matters including:

Agriculture-Related Cases
  • Lead counsel for Northwest Dairy Association in a successful defense of a breach of fiduciary duty, fraud, and breach of contract case with a multimillion-dollar claim over forward milk price contracts.

  • Lead counsel for DuPont in a 10-year-long agricultural products liability defense case, dealing with over 100 plaintiffs claiming herbicide damage to their crops. The four-month bellwether trial was the second-longest jury trial in Idaho's history.

  • Lead defense counsel in numerous agricultural products liability cases dealing with sprinkler systems, crop damage, and wrongful death.

  • Lead counsel in feed lot/nuisance case, successfully defended and maintained rights to operate feed lot.

  • Lead plaintiff's counsel in a multimillion-dollar commercial crop loss case against a major chemical producer.

  • Lead counsel for Amalgamated Sugar cooperative in an agricultural-related breach of contract/antitrust case.

  • Lead plaintiff's counsel in a commercial condemnation case dealing with the U.S. Bureau of Land Management.

Environmental Cases
  • Lead local counsel for a multimillion dollar environmental contamination coverage dispute involving over 20 insurers and overlapping and layered insurance policies.

  • Lead counsel in several environmental cleanup matters and in several insurance coverage cases for a regional insurance company.

Damages, Injury and Wrongful Death Cases
  • Lead counsel in a large utility fire resulting in the destruction of 9 homes, damage to an additional 9 homes, and one fatality.

  • Lead counsel in two brain injury cases, resolved favorably for the clients.

  • Lead counsel for defendant in a multimillion dollar, 80-plaintiff wrongful-death claim in New York City.

  • Lead plaintiffs' counsel for two wrongful-death claims arising from a commercial airliner crash, and member of the plaintiffs' steering committee in Detroit, Michigan which resulted in multimillion dollar recovery for clients.

Jury Trials
  • Daw v. Amalgamated Sugar Company (crop loss defense)

  • Bywater v. Bywater (personal injury defense)

  • Hatfield v. McMurray (personal injury defense)

  • Bohrn v. Dueker (personal injury defense)

  • Jacob v. USF&G/JAB/Bradford (fraud defense)

  • Harper v. Magic Valley Potato Shippers (contract dispute)

  • Pearson v. Prime, Inc. (personal injury defense)

  • Fleck v. Western Realty (fraud defense)

  • Henderson v. Jacobsen (real estate mortgage foreclosure)

  • Hamilton v. Winslow (fire loss defense)

  • Cheney v. Cheney (personal injury defense)

  • Brennan v. Shildmyer (collection on promissory note)

  • King v. Leffler (personal injury defense)

  • George v. Griffin (destruction of a potato cellar defense)

  • Greeninger v. Wood River Auto (personal injury defense)

  • Griffith v. Latham & Chrysler Corp. (lemon law defense)

  • Latham v. Phillips (contract dispute)

  • Payne & St. Leon v. Skaar (nuisance defense)

  • U.S.A. vs. 11.24 acres (condemnation action)

  • Thompson v. P.S.I. (personal injury defense)

  • Mendoza v. Lind (farm personal injury defense)

  • Guerrero v. Bob's Farm (farm personal injury defense)

  • Wassertrom v. Whitehead (construction defect case)

  • Marlin v. MacKelly (personal injury defense)

  • Wooley v. Dunbar (commercial property contract suit)

  • Bybee v. Amalgamated Sugar Company (antitrust; breach of contract; breach of fiduciary suit)

  • Adams v. DuPont (mass agricultural product liability suit)

  • Aardema v. Northwest Dairy Association (large breach of fiduciary duty; fraud and breach of contract suit)

Court Trials
  • Mingo v. Greene (defense of an insurance agent)

  • Dick v. Geist (covenant not to compete action)

  • Heida v. School Distr. 411 (improper dismissal)

  • Squires v. Roy Raymond Ford (negligent repair claims)

  • Pohlman v. Tsuga Hata (personal representative estate contest)

  • Ginder v. Kelley Nurseries (chemical overspray defense)

  • American Heart Association v. Tierney (embezzlement prosecution)

  • Williams v. Bailes (personal injury defense)

  • Monsanto v. Pacific Corp (utility contract dispute)

Other Significant Cases Held
  • Happy Land Social Club Fire, New York City (wrongful death mass action)

  • Raymond v. Comair, Detroit (aviation wrongful death case)

  • University of Idaho Foundation v. Civic Partners (commercial breach of contract claim)

  • Paoloni v. Albertsons (corporate fiduciary duty claim)

  • Carmella v. Albertsons (class action defense)

  • Gabriel v. Albertsons (wrongful discharge claim)

  • Hot Fuels MDL Case, Kansas City (corporate multi-district litigation)

  • Mueller v. St. Luke’s Regional Medical Center (constitutional rights; breach of fiduciary duty dispute)

  • Gary's Westland Motors v. Olander Paving (construction contract dispute)

  • Chappel v. Fleming Foods (non-competition dispute)

  • Zozula v. Purely Supreme Foods (breach of employment contract)

Appellate Court Reported Decisions
  • Clark v. St. Paul Prop. & Liab. Ins. Co. (declaration judgment)

  • Hirst v. St. Paul Fire & Marine Ins. (insurance coverage dispute)

  • Bartlett v. Peak (personal injury dispute)

  • Strout Realty v. Milhouse (broker's commission dispute)

  • Standlee v. St. Paul Fire & Marine, Inc. Co. (professional liability and office liability insurance policies)

  • Jerome Thriftway Drug v. Winslow (fire loss dispute)

  • Culp v. Tri-County Tractor (subordinated promissory note dispute)

  • Arrington v. Arrington Bros Const. (commercial construction contract dispute)

  • Latham Motors v. Phillips (lemon law case)

  • Mutual of Enumclaw v. Wilcox (insurance coverage dispute)

  • Payne v. Skaar (nuisance case)

  • Consolidated AG of Curry, Inc. v. Rangen, Inc. (commercial lease case)

  • Weaver v. Searle (commercial agricultural crop dispute)

  • Storrer v. Kier Construction Corp. (arbitration contract dispute)

  • Comer v. County of Twin Falls (zoning dispute)

  • Mutual of Enumclaw Life Ins. v. Lincoln (insurance coverage dispute)

  • West v. Sonke (wrongful death action)

  • Pfau v. Comair Holdings, Inc. (aviation wrongful death dispute)

  • Erkins v. Stoel Rives (errors & omissions claim)

  • Paolini v. Albertsons (securities/corporate fiduciary duty claim)

  • University of Idaho v. Civic Partners (breach of contract claim)

  • State of Idaho v. Maybee (constitutional rights dispute)



Speaking Engagements


Bar Admissions

Court Admissions


  • Idaho State Bar Professionalism Award, 2018
  • Idaho State Bar Service Award, 2016
  • Idaho Legal History Society Byron J. Johnson Award, 2016
  • Benchmark Litigation, Local Litigation Star, 2012-2018
  • Mountain States Super Lawyers, Business Litigation, 2007-2019
  • Mountain State Super Lawyers, Top 100 Lawyers, 2015-2019
  • The Best Lawyers in America© Lawyer of the Year, Bet-the-Company Litigation - Boise, 2011, 2015, 2018
  • The Best Lawyers in America© Bet-the-Company Litigation, Commercial Litigation, Litigation - Antitrust, Litigation - Securities, Litigation - Trusts & Estates, 2007-2020
  • Chambers USA: America’s Leading Lawyers for Business, Litigation: General Commercial, 2006-2019
  • Idaho Chapter of the Federal Bar Association, Exemplary Lawyer Award, 2013
  • Golden Eagle Award, DuPont Legal top award for excellent legal services, Wilmington, Delaware, February 2012
  • International Who’s Who of Product Liability Defense, 2011-2016
  • Martindale-Hubbell®, AV Preeminent® Rating

Professional and Civic Affiliations

  • Idaho Chapter of the Federal Bar Association, Member, 2004-2018
  • President, 2016-2017
  • Ninth Circuit’s Lawyer Representative, U.S. District Court and U.S. Bankruptcy Court of Idaho, 2012-2015
  • Ninth Circuit Lawyers Representative Coordinating Committee Member, 2012-2015
  • American College of Trial Lawyers (ACTL), Fellow
  • National Foundation Board Member/Treasurer, 2008-2013
  • State Chair, 2004-2006
  • Jury Committee Chair, 2005-2007
  • International Academy of Trial Lawyers (IATL), Fellow
  • State Chair 2011-2016
  • International Association of Defense Counsel (IADC), Member
  • Board of Directors, 2001-2005
  • Executive Committee, 2003-2005
  • President, 2003-2004
  • Lawyers for Civic Justice (LCJ), Member
  • Board of Directors, 2001-2007
  • Executive Committee, 2004-2007
  • President, 2005-2006
  • IADC Corporate Counsel College, Dean, 2008
  • Idaho Federal District Court Local Rules Committee Member
  • American Bar Foundation, Fellow
  • Co-State Chair, 2016, 2017
  • University of Idaho Law School Advisory Council, 2013-2019
  • American Inns of Court, Member
  • President Boise ID Inn, 2007, 2008
  • American Bar Association (ABA), Member
  • Idaho Bar Association, Member
  • FACES of Hope Foundation Board, Member
  • Idaho Community Foundation Board of Directors, Member
  • Idaho Shakespeare Festival
  • Board of Trustees, 2011-present
  • Executive Committee, 2013-present
  • President, 2015-2016
  • St. Luke’s Regional Medical Center Strategic Initiatives Committee, 2008-present (Chair, 2018-present)
  • State Membership Chair, U.S. Supreme Court Historical Society, 2006-2008, 2012-2018
  • Idaho Legal History Society, Member
  • Treasurer, 2012-2016
  • Board of Directors, 2014-2016
  • Learning Lab - Advisory Committee, 2016-2017
  • American Heart Association
  • Chair, Board of Directors, Idaho Chapter, 2014
  • Lifetime Achievement Award, 2018
  • Gold Heart Award, 2004
  • National Chair, Board of Directors and Volunteer CEO 1999-2000
  • National Co-Chair, Tobacco Settlement Review Committee 1997
  • National – AHA Meritorious Achievement Award
  • National Board of Directors, 1994, 1996-2001

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