Dennis is the co-founder and control shareholder of The Reserve Trust Company. Dennis has over four decades of experience of banking law experience and has been named one of the top 20 banking lawyers in the country. From 1996 until 2012, Dennis was the lead class counsel for approximately 500,000 individual Indian trust beneficiaries in an action in equity in the US District Court for the District of Columbia against the Secretary of the Interior, the Secretary of the Treasury, and the Assistant Interior Secretary-Indian Affairs in Cobell v. Salazar, to enforce trust duties owed by the United States to plaintiff classes since 1887. On December 7, 2009, the parties executed a landmark settlement agreement, wherein the United States government would pay $3.4 billion. The settlement amount at that time was the largest settlement with the federal government in American history.
Prior to Cobell, Dennis focused on national, cutting edge and otherwise unique public and private law financial industry matters, first as an attorney for the U.S. Comptroller of the Currency, U.S. Treasury Department (1976-1980) (resident in Washington, D.C. & Denver, Colorado (as Regional Counsel)); as a partner in Gorsuch, Kirgis, Campbell, Walker and Grover, Denver, Colorado; and, thereafter, as a partner in major international law firms, e.g., Kirkland & Ellis; Squire, Sanders & Dempsey; and Foley, Hoag & Eliot, principally in Washington, D.C., e.g., to obtain approval from the Comptroller of the Currency for a general business corporation chartered under D.C. Law to engage in the banking business, the deposits of which were insured by the FDIC (which was exempt from ownership, product, and geographical restrictions of the Bank Holding Company Act of 1956, as amended); and the development of an annuitized, tax-deferred, FDIC approved insured deposit, for which issuance was authorized by the U.S. Comptroller of the Currency.