John C. Wahl, CFP®

Financial Advisor, Managing Partner

Phone: 314-924-8009

John provides his clients with customized, comprehensive financial advice to help them achieve their goals and live the life they want. As a CERTIFIED FINANCIAL PLANNERTM professional, he specializes in investment strategy, wealth accumulation, education planning, and retirement planning with families and business owners. Furthermore, as a CERTIFIED FINANCIAL PLANNERTM professional, one of the duties owed to his clients is the fiduciary duty, whereby he acts as a fiduciary when providing financial planning to a client. Please see the CFP Board's Code of Ethics and Standards of Conduct.

Many of John's clients came to him because they no longer wanted the hassle of managing their own portfolios or they were not sure that they were managing it as efficiently and effectively as they wanted. Others were nearing retirement, had a 401(k), and wanted a retirement plan. In addition to investment selection, John includes comprehensive strategies for his clients such as tax-advantaged strategies, risk management solutions such as insurance, and income strategies.

A St. Louis native and CBC graduate, John received his undergraduate degree and MBA from Ole Miss. Today, he puts his experience to work with a passion to improve the financial lives of those around him. That is also one of the main objectives for co-founding One Bridge Wealth Management: to continuously improve the financial lives of his clients and the services delivered to them.

John lives with his wife and son in St. Louis. Other than spending time with them, he enjoys spending time at his family farm, golfing, hunting, traveling, and anything outdoors.

Contact him today to learn more about his services and how One Bridge Wealth Management can help you reach your financial goals.



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Mark Witthaus

Financial Advisor, Managing Partner

[email protected]





Phone: 314-924-8008


Mark, a native of Hermann, Missouri, got his start in the financial field right after graduating from Truman State University in December 2001. He's always had a fondness for saving, investing, and all things numbers since high school. It was natural then that his first official job out of college was in the financial field, where he was hired to be an advisor and has never looked back.

Those early days and subsequent years in the profession have taught him what it truly means to be an advisor. It's not just about investing and crafting portfolios for clients, although that's certainly a major role. It's also adding value through social security planning, reviewing debt management questions, just to name a few. He views his job as one in which listening and communicating easy-to-understand plans are tantamount to his practice.

Today, while he has a relatively broad base of clients, his specialty is in serving the unique needs and dynamics associated with teachers and attorneys.

Today, Mark lives in O'Fallon, Missouri, with his wife, Mary Ann, and kids (Ellie, Ryan, and Claire). Outside of his professional life, he loves to watch his kids play various sports, and most weekends you can find him in a gym or at a soccer field.

Louise Gardner

Client Service Associate, Registered Staff


Phone: 314-924-8007

Louise assists John and Mark in many aspects of wealth management and client service. She brings years of friendly, professional customer service and office management experience to the firm. She approaches each task with cheerfulness and finds the greatest value in the process of helping people achieve their goals. 

Louise is married to Jim and has three grown children, whom she loves on as much as possible. In her spare time, she enjoys her home life with Jim, and together, along with Maggie, the family border collie, they go on as many outdoor adventures as possible. Her special interest is in working with seniors and assisting them with in-home care. 

Louise holds FINRA Series 7 and 66 securities registrations.