About Us


Meet the team that builds possibility.

Waste no


Meet Us

The Right Team

Richard Tanenbaum

Chief Executive Officer


Chief Executive Officer

As Gardner Tanenbaum Principal Owner and CEO, Richard Tanenbaum brings more than 35 years of commercial real estate experience to every project the company undertakes. Throughout his tenure, Mr. Tanenbaum has demonstrated the ability to provide visionary leadership and quality real estate solutions for corporate and aerospace clients needing commercial space in the Oklahoma market.

Mr. Tanenbaum has vastly expanded the asset base of the Gardner Tanenbaum commercial portfolio and enhanced the company’s capabilities and expertise in various types of construction, including multi-family, industrial, retail and office. Since 1997, he has overseen the growth of the company’s commercial portfolio, expanding it from 800,000 square feet to more than 8,000,000 square feet. Mr. Tanenbaum has completed nearly 50 projects totaling more than $500,000,000, making Gardner Tanenbaum one of the largest developers in Oklahoma. In 2020, Mr. Tanenbaum negotiated one of the largest commercial real estate transactions in Oklahoma history, selling the Boeing Oklahoma City campus for more than $124.7 million to west coast investors.


Becky Tanenbaum Mallace




As principal of Gardner Tanenbaum, Becky Tanenbaum Mallace joined the company in 2014 and leads the Real Estate Investments division, Tanenbaum Equity Partners. In addition, she leads Gardner Tanenbaum’s Dallas office.

Becky has extensive experience in government-leased assets, multi-family, office and industrial sectors. She is involved with the acquisition and ongoing management of Gardner Tanenbaum’s investments. She oversees the research of viable purchases, transactions, property management and regularly engages in negotiations and operations activities. In addition, she handles corporate communications, marketing, research and special projects.


• B.A. in Fine Arts and Design from George Washington University

Stephen Tanenbaum




Stephen Tanenbaum is an internationally renowned real estate developer based in both Sãoo Paulo, Brazil and Oklahoma City, USA. He is the son of business mogul, Richard ‘Dick’ Tanenbaum, who founded the real estate empire Gardner Tanenbaum Holdings (GTH).

The talented Tanenbaum’s are a powerful family force. In addition to Richard and Stephen, the matriarch, Glenna, is incredible on the design side and daughter Becky leads the Real Estate Investments division, Tanenbaum Equity Partners.

Stephen is fluent in English, Spanish, and Portuguese and has a worldwide reputation as a knowledgeable and passionate innovator in the industrial sector of the real estate development industry.

He earned his degree from The George Washington University in international relations with a focus on Latin America. After graduation, he spent several years developing enterprises in Brazil, including time at Embraer – one of the largest aerospace manufacturers in the world.

Stephen returned to the U.S. in 2005 to join Gardner Tanenbaum where he mastered all aspects of development including design, construction, finance, leasing and management for residential, industrial, and commercial properties.

In 2011, Stephen returned to Brazil, capitalizing on his expertise to manage
international investments and handling institutional capital funds. He joined GTIS Partners to oversee industrial property development and managed millions of square feet of industrial space in Brazil and expanded developments to the US including Seattle, Dallas, Atlanta, Phoenix,Nashville and several other U.S. cities.

Stephen now splits his time between São Paulo and Oklahoma City working as the chief principal of GTH which has developed more than $1.2B worth of property worldwide including 8.2M square feet among multifamily, commercial, and industrial properties.

In addition to his passion for real estate and philanthropic investments, Stephen’s deepest love is for his family. He and his wife Juliana have been married for 15 years and are the proud parents of two very busy children.


Cindy Murillo

Chief Operating Officer


Chief Operating Officer

Cindy Murillo joined Gardner Tanenbaum in 2013 and has more than 20 years of experience in commercial construction, multi-family, student housing and military housing. She has expertise across the entire spectrum of development, including ground-up commercial construction and project management in both commercial and residential real estate. Furthermore, she has worked in all areas of the multi-family industry from project development, leasing to sale.

Cindy leverages her knowledge and experience to develop relationships with clients and staff to execute all components of project development from site planning to contract coordination and project development.


• Licensed Active Broker Proprietor – Oklahoma Real Estate Commission
• Certified Defense Property Manager I & II – Institute of Real Estate Management (IREM)
• Commercial Real Estate Council (CREC)
• Oklahoma City Association of Building Owners and Manager (BOMA)
• Certified Mediation Practitioner – Civil/Commercial Employment

Erik Gumerson

Vice President of Construction


Vice President of Construction

Since joining Gardner Tanenbaum in 2003, Erik Gumerson has been involved in more than 30 projects totaling $173,875,500 and 2.3 million square feet. He is responsible for developing projects from design through completion. These projects range from aerospace developments, such as two MRO Hangers at WRWA and a corporate campus for Boeing, to numerous industrial concrete tilt up facilities ranging from 100,000 to 300,000 square feet.

Erik’s residential portfolio includes four ground-up new construction projects for garden style and “Big House” apartment homes, as well as two exciting high-rise retrofit buildings. He has built multiple office buildings including smaller, condo style units, overseen retrofit construction projects, and developed Class A office space. Erik retains a comprehensive skill set for property development, including lease proposal, design, permitting, construction management, and occupancy completion.


• Earned a degree from the University of Oklahoma

Matt Donovan

Vice President of Finance


Vice President of Finance

Matt Donovan joined Gardner Tanenbaum in November 2008. As Vice President of Finance, he brings more than 19 years of experience in finance, accounting, marketing, retail, sales and customer service to the Gardner Tanenbaum team.

Armed with a thorough understanding of his field, Matt has been involved in the financing of more than 15 development projects, where he contributed to the acquisition, transition of ownership and management. He has taken a leadership role in managing the company’s required financial reporting and regularly analyzes evolving business activities. In addition, he ensures accuracy and accountability by creating numerous efficiency tools in order to streamline operations and ensure maximum effectiveness of the company’s finances.

Matt expedites the funding of new projects by collaborating with various financial institutions to ensure Gardner Tanenbaum remains in compliance with all loan covenants for both completed and ongoing projects.


• B.S. in Business Management from Baker University

Darrin Malone

Sr. Director of Facilities


Sr. Director of Facilities

Darrin Malone joined Gardner Tanenbaum in 2008 and is the Senior Director of Facilities. Darrin is responsible for facilities management of all multi-family and commercial properties.

Bringing more than 27 years of experience to the team, Darrin maintains processes within the Gardner Tanenbaum operation. Darrin is driven by the purpose of improving quality of life and productivity of the core business. He oversees the environment, health and safety, fire safety, security, testing and inspections, building maintenance, cleaning, space allocations and operations of all Gardner Tanenbaum properties.


• 2012 Apartment Association of Central Oklahoma NOVA Award

Debbie Bruner

Accounts Payable & Human Resources


Accounts Payable & Human Resources

Debbie Bruner brings more than 19 years of experience in maintaining accounts payable, treasury management and human resources preservation to Gardner Tanenbaum. Debbie is responsible for all corporate, commercial, industrial and multi-family payables. She maintains more than three dozen entities. In addition to the upkeep of day-to-day payable operations, she provides support across all departments within the company, including tax liability and payments, permit submittal and payment benefits.


• Manages more than 36 entities within Gardner Tanenbaum

Jeff Mullins

Accounting & Operations


Accounting & Operations

Jeff Mullins maintains Gardner Tanenbaum’s accounts payable and accounts receivable operations. He assists in nearly every facet of the company, from helping with presentations and marketing, to performing basic IT for the office. Prior to joining Gardner Tanenbaum, Jeff spent 10 years as an accounting manager for a local logistics company and five years working for an oil and gas services company. His diverse experience in accounting, IT and customer service is critical to the management of the company.


• Has developed tools and programs that have improved efficiency for the company

Amy Rachel

Operations Coordinator/Marketing


Operations Coordinator/Marketing

Amy Rachel joined Gardner Tanenbaum in 2019 beginning in Corporate Accounting and transitioning to Operations Coordinator for the Multi-Family Property Division. Amy is responsible for the daily operations of all Multi-Family communities and staff to bring the highest level of customer focus to our residents. She is also responsible for the Marketing of Multi-Family properties that drive the high occupancy rates while maintaining a financially stable environment. Amy brings 15 years of Corporate Accounting and puts her knowledge to the financial impact of property ownership.


Certified Apartment Portfolio Supervisor (CAPS)

The Gardner Tanenbaum Collection

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Our mission is to build transformational developments that embolden communities.

Our Values


No guts, no glory

We are the future of possibility. We will swing for the fences because ambitious projects are our ordinary. We embrace calculated risk and bet on ourselves.


We deliver with confidence

Our clients can count on us, period. Our distinction is in our execution, and our word is our promise.


Progress isn’t optional

We define the unique marriage of innovation and resolve. Our commitment to professional growth resounds within every project, every partnership, and every interaction.