Marjorie affiliated with Jones Walker after serving as Secretary of the Louisiana Mineral and Energy Board and Assistant Secretary of the Louisiana Department of Natural Resources, Office of Mineral Resources, where she oversaw the granting and administering of mineral leases, storage agreements, and alternative energy agreements on state-owned land and water bottoms. While serving as Secretary of the Louisiana Mineral and Energy Board, Marjorie undertook a comprehensive revision of Louisiana's statutory scheme relating to leases for underground storage.

In addition to her upstream oil and gas practice, Marjorie routinely serves as project counsel for large energy infrastructure projects, including pipelines, LNG and liquefaction facilities, crude oil and hydrocarbon liquids export facilities, hydrocarbon storage facilities (salt dome and depleted reservoir storage), solution-mining facilities, petrochemical and chemical plants and refineries and commercial saltwater disposal facilities. Marjorie also represents a number of energy service companies and renewable energy companies.

Marjorie understands that successfully and efficiently navigating regulatory and land use issues can dramatically increase the odds of success of a project and works tirelessly to help ensure that clients' projects proceed through the regulatory process in a timely and efficient manner.

Marjorie also has extensive experience in the construction and engineering arena with respect to contractor and engineering licensing, having assisted a number of clients in acquiring contractor and engineering licenses throughout the United States when numerous licenses are needed in short periods of time in connection with transactions or projects.

After clerking with the Honorable Frank J. Polozola in the US District Court for the Middle District of Louisiana, Marjorie was in the private practice of law from 1992 to 2006, during which time she concentrated on civil litigation, including environmental and toxic tort litigation. Previously, she served as campaign manager to her father, W. Fox McKeithen, during his initial campaign for the office of Louisiana Secretary of State.

Marjorie is currently an appointed member of the Interstate Oil and Gas Compact Commission and serves on the Board of the Louisiana Oil & Gas Association.