Many agencies, organizations, and researchers have called for the incorporation of inquiry-based learning in college classrooms. Providing inquiry-based activities in laboratory courses is one way to promote reformed, student-centered teaching in introductory geoscience courses. However, the literature on inquiry has relatively few geoscience examples and features an array of modifiers that complicate instructor efforts to identify or adapt inquiry-based activities for their courses. We review several measurement protocols developed to assess inquiry in laboratory activities. We apply one of these to assess the level of inquiry present in four published physical geology laboratory manuals. While the majority of activities used in the published manuals were classified at low levels of inquiry, these manuals also contained examples of higher-level activities that were not identified in previous analyses. We describe the development of inquiry-based lessons for inclusion in a freshman-level physical geology laboratory course at a large public research university in the southeast U.S. and apply the same protocol to assess the laboratory course activities and discuss how some activities were adapted to increase inquiry levels. We discuss how other instructors or laboratory course developers can adapt existing activities to incorporate higher levels of inquiry in their laboratory courses, matching them with the type of information or skill they want students to learn.