About 


GTM Holdings, LLC (“GTM”), as a successor to American Communities, is a real estate development company (the “Company”) dedicated to providing high quality housing for the next generation: “Generational Thinking Matters.”  GTM specializes in the development, construction and operation of multifamily affordable and market rate housing utilizing various sources of private and public financing.

Who We Are

MARK WALTHER has an extensive background in multifamily real estate development and construction having been active in the Housing Tax Credit program since 1987.  As a senior executive at a national syndicator Mr. Walther held multiple positions including General Counsel as well as President of its broker dealer, holding 3 securities licenses.  That firm owned approximately 17,000 units nationwide before being sold to AIMCO in 2000.  Mr. Walther then co-founded American Communities in 2000 where, over 16 years, the firm built and developed 17 properties with 874 multifamily units throughout the Los Angeles area.  American Communities’ portfolio consists primarily of tax credit buildings financed with an array of specialized financing programs. Mr. Walther holds a Bachelor of Arts degree with high honors from the University of California, Santa Barbara,  a J.D. Degree from the University of California, Davis School of Law and a California General Contractor’s license.  Civically, Mr. Walther along with his wife, Michelle, are philanthropically involved throughout Los Angeles and give to the community as President of the Getty House Foundation, a 501(c)(3) organization dedicated to civic education, community engagement, and the preservation of Getty House, the official residence of the Mayor of Los Angeles.  Mr. Walther also sits on the Advisory Council of the Los Angeles Neighborhood Land Trust which sponsors inner city parks throughout Los Angeles.

ADRIENNE BUSSELL is Assistant Vice President of Development for the Company.  Her responsibilities include coordinating development activities and assisting in the financing of each development which the Company pursues.  Ms. Bussell oversees all lender and syndication due diligence, preparesfinancing applications for the various leveraging sources and is primarily responsible for the Company’s administrative aspects.  Prior to joining the firm, Ms. Bussell worked at American Communities since 2007 where she supervised asset management of the company’s portfolio and was principally responsible for the asset management and supervision of the following programs: Affordable Housing Tax Credits, HOME Investments Partnerships Program, Los Angeles Housing and Community Investment Program (“HCID”), Community Development Commission of the County of Los Angeles and Transit Oriented Development (“TOD”).  Ms. Bussell attended the University of California, Santa Barbara, is an active member of the Junior League of Los Angeles and currently volunteers with Reading to Kids, an organization dedicated to children in low-income neighborhoods.

SAM CASTELAN is Director of Planning for Real Estate Development and Construction.  In that capacity, Mr. Castelan advises on strategic locations for new developments analyzing market trends and developing architectural, financial and construction cost budgets for each site.  Mr. Castelan’s previous experience includes serving as the Vice President for professional activities for Architects College, President and founder of LIDEM, a non-profit organization that works in policy advocacy for community and economic development and more recently, as the Hotel Acquisitions Senior Associate for strategic planning at City Express Hotels.  Mr. Castelan’s academic background includes a Master of Urban Planning, a Master of Public Administration, a Graduate Certificate of Real Estate Development, an MBA with honors and a Bachelors Degree in Architecture all from the University of Southern California.

RONALD MAYHEW is the Company’s Director of Development and brings thirty years of experience in the process of real estate development from three perspectives: public agency representation, private engineering and consulting and as an owner, developer of multifamily housing.  Previously Mr. Mayhew served as a Vice President of Casden Properties in Beverly Hills, California, for 18 years where he was active in all aspects of the development process from site acquisitions, design, public hearing presentations for the production of major residential and mixed use projects throughout Los Angeles. Thereafter, Mr. Mayhew served as a Vice President of Security Capital (now Archstone) in Atlanta, Georgia, for 4 years, building residential apartment complexes throughout the southern states.  Mr. Mayhew has a Bachelor of Science in Urban Planning form California State Polytechnic University Pomona.

BOB HILDEBRAND is Director of Construction for the Company’s construction affiliate, United Building Company.  Mr. Hildebrand has been active in construction for over 40 years and, for 25 years, served at Casden Properties in Beverly Hills California where he oversaw the development and construction of more than 20,000 apartment units and 5,000 single family homes.  Mr. Hildebrand served in several executive positions and facilitated the sale of the portfolio to Apartment Investment and Management Company (AIMCO) in 2002. Mr. Hildebrand is a licensed General Contractor in the states of California and Hawaii and is on the advisory Board of the National Multifamily Housing Conference.  He obtained a Bachelor of Science from Temple University in 1967.

JONATHAN LITTRELL is Counsel to the Company and, in that capacity, oversees the legal activities of the Company and its affiliate construction company, UBC. Mr. Littrell has a wide range of experience in affordable housing having worked for the Community Redevelopment Agency of Los Angeles in 2005 as well as with a prominent sponsor of affordable housing thereafter in 2006 and 2007. Mr. Littrell is a Partner in the Beverly Hills law firm of Raines Feldman, LLP, where he represents public and private companies in acquisitions, joint ventures, financing transactions and the private placement of both debt and equity instruments. Mr. Littrell received his law degree from Loyola School of Law, Cum Laude, as well as his MBA from Loyola in 2006. He is a Graduate of the University of California at Davis, High Honors, in 2004.