Randi Martinsen is an American geologist and senior lecturer in the Department of Geology and Geophysics at the University of Wyoming.

[1] Martinsen has worked extensively on the Western Interior Cretaceous basin with a particular interest in stratigraphic trap exploration, paleotectonic influences on depositional systems and clastic reservoir characterization.

[2] Martinsen is a former president (2014 - 2015) and the second woman ever elected to head the American Association of Petroleum Geologists Foundation (AAPG), an organization that provides educational programs, scientific research, and engineering services in communities around the world.

[6] Five years after starting work at Cities Service Company in Denver, she married Jim Steidtmann, a geology professor at the University of Wyoming.

[6] In 1979, Martinsen submitted an abstract to the Rocky Mountain Section American Association of Petroleum Geologists about the Hartzog Draw, a giant oil field.

"[6] Upon hearing the reason for the rejection, Martinsen fought back by forcing the program chair to reverse his decision and later offered her to present.

[14][15] The focus of these pertain to depositional system analysis, sequence stratigraphy, tectonics and sedimentation, anomalous pressures, hydrocarbon accumulation, and tight gas sandstones.

[15] Along with these topics, Martinsen has also published course notes and field trip guides from her work at the University of Wyoming.