This report documents specimen rescue activities for the Rikuzentakata City Museum in Iwate Prefecture, Japan, after the 2011 Tohoku Earthquake and Tsunami. The museum was established in 1959 and had housed about 150,000 cultural and natural-science specimens. The museum was devastated by the tsunami, leaving five museum staff killed and one missing. Many specimens were lost, while the rest were submerged in muddy water and buried under debris. In May 2011, much of the tsunami-damaged material was salvaged and moved to the former Oide Elementary School, where two major stabilization treatment operations were undertaken for geological specimens (1-5 August and 4-7 October 2011). Thirty-three people (mainly specialists in geology and paleontology) from 24 institutions participated in the operations and later in supplementary work to complete treatment and cataloguing. In all, 3283 geological specimens, mostly local Carboniferous-Permian fossils, were treated in these operations. The original specimen registry and electronic data were lost in the tsunami, and further curatorial work is needed to restore the collection data. The rescue activities have been publicized at academic conferences and in museum exhibitions, attracting media attention and public support. A mutual support system among research institutions needs to be established to dispatch specialists to stricken areas. We believe that the strong leadership of the project leaders and their support staff was crucial to the operation. Up-to-date local information before arrival at the scene, well-planned on-site scheduling, with work manuals for allotted tasks and arrangements for local transportation, and background information on the academic and cultural importance of the rescued collection were particularly helpful to the participants.