There is only 1 species of salamander in Yellowstone NP.
The blotched tiger salamander (Ambystoma tigrinum melanostictum) is it. This individual found its way from the Norris Geyser Basin to the nearby museum buildings on a rainy day, a good time to spot these amphibians as theymust keep their skin moist.
Photo courtesy of Rosa Prasser
(via: Yellowstone National Park, WY, USA)