Our Story

Mammen & Null, Lawyers, LLC was originally established in 1984 as D. Dale Mammen Law Office. After serving fourteen years as Union County's District Attorney, Dale Mammen opened his sole practitioner law office focusing on Estate Planning, Family and Business Law, Guardianships, Conservatorships, and Probates.

J. Glenn Null

In 2004, J. Glenn Null joined the firm as a practicing attorney and took over as managing partner in 2010. Prior to practicing law, Glenn and his wife Heather operated the Sears Authorized Retail Dealer in Island City.  Glenn is the Chair of the Grande Ronde Hospital Foundation and Past President of La Grande Rotary Club and volunteers extensively within Union County.

Glenn earned his law degree from Willamette University in Salem, Oregon and completed undergraduate studies at Whitman College in Walla Walla, Washington. He lives in La Grande with his wife, two daughters, and a charming hound.

Zach joined Mammen & Null in 2018.  After completing his undergraduate studies at Eastern Oregon University he attended Willamette University College of Law.  He lives in La Grande. 

Zach Nice

D. Dale Mammen

Mammen & Null is housed in the historic Anthony - Buckley House constructed in 1902. Located at the intersection of Sixth and Penn Streets, this charming Victorian structure provides a warm and friendly environment to clients of all ages. The house in decorated with many pieces of period furniture and historic memorabilia collected by Dale and his wife Virginia.


Our Team

J. Glenn Null, Lawyer

Zach Nice

Sandi Johnson, Legal Assistant

Jessika Oswald, Legal Assistant

Heather Null, Office Manager

D. Dale Mammen, Lawyer (retired)