Meet the Team

Richard Tanenbaum

Chief Executive Officer


  • Tulane University
  • Bachelor of Arts – Economics


Richard is the principal owner of Gardner Tanenbaum Holdings and brings over 35 years of commercial real estate experience including development, acquisition, and brokerage. Richard owned and operated over eighteen restaurants in Texas, including the Atchafalaya River Front Café, before joining GTH. Throughout his tenure, Richard has demonstrated the ability to provide creative and quality real estate solutions for corporate users needing commercial space in the Oklahoma market.

Project Experience

Since taking over as CEO, Richard has vastly expanded the asset base of GTH’s commercial portfolio as well as the company’s capabilities and expertise in different types of construction including industrial, office, retail, and multi-family. Since 1997, he has overseen the growth of the company’s commercial portfolio from 800,000 square feet to over 6,000,000 square feet. Richard has completed over 35 projects totaling more than $350,000,000 making GTH one of the largest developers in Oklahoma.

These projects have ranged from single and multi-tenant warehouse and distribution facilities, large single tenant office complexes for companies such as Boeing, Northrop Grumman, a hangar complex for ARINC, as well as over 1,000 apartment units in 4 different multi-family communities.

Professional Affiliations

  • Commercial Real Estate Council (CREC)
  • Greater Oklahoma City Chamber of Commerce Board Member
  • Greater Oklahoma City Chamber of Commerce TRDC Co-Chairman

Erik Gumerson

Vice President of Construction


Prior to joining Gardner Tanenbaum Holdings, Erik worked for Timberlake Construction and Concrete Services, Inc. in Oklahoma City. Erik served in the capacities of project manager as well as project foreman for several large build-to-suit projects.

Project Experience

Since joining GTG in 2003, Erik has been involved in over 20 projects totaling $173,875,500 and 2,316,000 sf. The projects have ranged from a MRO Hangar for ARINC, Corporate Office Facility for Boeing, 269 residential homes at Liberty Trials, and 708 apartments at the Lincoln at Central Park.

Cindy Murillo

Chief Operating Officer


Cindy brings 23 years of experience from the commercial construction, multi-family, student housing and military family housing markets to Gardner Tanenbaum Holdings. Her experience spans from ground up commercial construction, project management in both commercial and the multi-family housing industry. Ms. Murillo utilizes her experience in sales, marketing, development, estimating, subcontracting and customer service to promote long term successful projects.

Project Experience

Ms. Murillo’s project experience includes project management of Oklahoma City’s first Luxury High Rise with a $17M retrofit for Gardner Tanenbaum/The Classen Luxury Apartments. Direct Management and over sight of privatizing over 3600 housing units for the United States Air Force (Tinker Air Force Base, Travis Air Force Base, Fairchild Air Force Base, and Lackland Air Force Base) and a private developer, Balfour Beatty Communities. Ms. Murillo’s portfolio included direct oversight of annual budgets in excess of $20M, a team of 83 employees, monthly occupancy and financial management, and achieved corporate goals in occupancy that averaged 95% consistently for the past 4 years.

Professional Designations

  • Certified Defense Property Manager I & II
  • Certified Mediation Practitioner – Civil/Divorce/Employment

Matt Donovan

Vice President of Finance


  • Baker University - Bachelor of Science – Business Management with emphasis in Accounting


Matt has over 13 years of experience in finance & accounting, management, retail, sales and customer service.

Project Experience

Since joining GTH in 2008 Matt has adapted the financial reporting to meet the requirements and analysis of our evolving business activities. Matt has passionately taken the initiative to ensure accuracy and accountability to the information provided by creating numerous efficiency tools to help streamline the day to day operations so GTH operates at maximum efficiency. Matt also works closely with various financial institutions to expedite the funding of new projects and to ensure GTH remains in compliance of all loan covenants.

Debbie Bruner

Accounts Payable


Debbie brings thirteen years of experience in maintaining accounts payable, treasury management, and human resources preservation to Gardner Tanenbaum Holdings.

Project Experience

Debbie is responsible for all corporate, commercial, industrial, and multi-family payables. She maintains over three dozen entities within GT Holdings. In addition to the upkeep of the day to day payable operations, Debbie assists with many other areas of the company including but not limited to property insurance, tax liability and payments, permit submittal and employee benefits.

Becky Tanenbaum Mallace

Principal, Dallas TX


Mrs. Mallace joined Gardner Tanenbaum Holdings in 2014 as a 4th generation of the Gardner Tanenbaum family. As head of the Dallas office, she leads the real estate investments division of GTH, focusing on building a General Service Administration portfolio throughout the US. Her responsibilities include overseeing the research of viable purchases, transactions and property management. Mrs. Mallace received a Bachelor of Arts in Fine Arts and Design from The George Washington University in 2004. Prior to working in commercial real estate, she honed her business and creative skills as a national sales director, buyer and technical designer.