Ya’aa’teeh. In 1959, NTUA started out as a small water utility in Shiprock, NM. In decades since, NTUA has grown into the largest multi-utility enterprise owned and operated by an American Indian tribe. NTUA is proud of its history and celebrates its progress. As a not-for-profit enterprise of the Navajo Nation, NTUA provides electric, water, wastewater, natural gas, solar energy, and communications services. We also take deep pride in our work and have the commitment to serve the multi-utility needs of the Navajo Nation. . In Navajo, the phrase “Niandeiilnish” means “We work for You”. In keeping with that principle, NTUA works for the People with teamwork and respect. That has been our primary mission since 1959.
About NTUA
Navajo Tribal Utility Authority®
Vision:
Enhancing our customers' lives through excellent utility services
Mission:
To provide safe, reliable and affordable utility services that exceed our customers' expectations
Values:
Customer Experience; Safety and Health; Integrity; Teamwork; Community Engagement and Support; Accountability and Respect
NTUA Management Board
NTUA Board Chairperson
Sidney B. Dietz II,
Mr. Dietz is a regulatory lobbyist for Pacific Gas & Electric in San Francisco specializing in energy efficiency, natural gas, and public purpose programs. He is a doctoral candidate in Energy and Resources at the University of California at Berkeley. He has a Master of Science Degree in Energy and Resources, and a Bachelor's Degree in Physics from UC Berkeley. Chairman Dietz was formerly manager of the Navajo Nation Air Quality Control Program where he led the development of the major source regulations and the creation of a certified air quality monitoring system, a first for the Navajo Nation.
Wynette R. Arviso
Ms. Wynette R. Arviso brings to NTUA more than 25 years of experience in management consulting, including organizational leadership, project management, and effective communications. She has provided professional management services to community and organizational development, with expertise in land planning and geospatial analysis. She currently owns and manages her own consulting firm. She attended and graduated from the University of Oklahoma with a Bachelor’s of Science in petroleum engineering, and a Master’s of Science in Industrial Engineering. She also holds a Master’s of Advanced Studies in Geographical Information Systems from Arizona State University.
Belinda P. Eriacho,
Ms. Eriacho has more than 26 years of experience in environmental, health and safety management. She is employed with Pinnacle West Capital Corporation in Phoenix where she serves as the Environmental, Health,and Safety Audit Leader. Her job focuses on compliance with federal, state, and local environmental, health, safety and Department of Transportation laws and regulations, advising the company on its scope of responsibility. She holds a Bachelor of Science Degree in Health Sciences, a Master's Degree in Technology, and a Master's Degree in Public Health.
Cathy Newby
Cathy Newby is the Director of Tribal Government and Customer Engagement with Public Service Company of New Mexico. With over 25 years of utility industry experience, she works closely with NM native tribes to establish, maintain, and enhance relationships between tribes and PNM. She has extensive background in Rights of Way, major infrastructure projects, including interconnection and renewable energy development on tribal lands. She is from Tohatchi, NM. Her primary clan is Bitter Water and her grandfather’s clan is Water’s Edge.
Mark Freeland
Mark Freeland is a former Navajo Nation Council Delegate who represented communities in the Eastern Navajo agency. He was appointed to the NTUA Management Board by the Resources and Development Committee of the Navajo Nation Council. Originally from Crownpoint, NM, Delegate Freeland represented 8 chapters including, Becenti, Lake Valley, Nahodishgish, Standing Rock, Whiterock, Huerfano, Nageezi, Crownpoint. His Navajo clans are: Tótsohníí (Maternal), Kinyaa'áanii (Paternal), Tsénjíkíní (Maternal Grandfather), and Tsenabahiłnii (Paternal Grandfather)
Anthony Montoya (Tony),
Dr. Montoya has over 35 years of utility management and operations experience, including over 25 years at the executive level with the US Department of Energy, Western Area Power Administration (WAPA). He served ten years as Chief Operating Officer which included extended periods as WAPA’s acting Administrator and as Chief Information Officer. He also served on utility governing boards for several organizations and taught graduate courses at Arizona State University. Since retirement, he has been working with DOE’s office of Intelligence and Counterintelligence. He holds a PHD from Arizona State University and MSEE from University of Colorado. He is also a registered Professional Engineer .
Harry Sonny Moore (Sonny)
Sonny Moore is a member of the Navajo Nation with 25 years of managerial experience in utility operations, having served as District Manager for three NTUA districts. Since his retirement, he has been active with local community governance and development, including serving as the Land Planning Committee Member and Secretary/Treasurer for four years. He now serves as a Chapter President for Tohatchi Chapter. He graduated with a bachelor’s degree in business administration from the University of New Mexico and a bachelor’s degree in liberal studies from Northern Arizona University. He also holds an associate’s degree from Northland Pioneer College and is currently pursuing a master’s degree from the College of Education at the University of New Mexico.
Navajo Tribal Utility Authority • P.O. Box 170, Fort Defiance, AZ 86504 • Phone: 1-800-528-5011 Copyright © 2025 NTUA - A proud Enterprise of the Navajo Nation