Perhaps the thing that is most constant about Yellowstone National Park is the change in the dynamics of its thermal activity. That, in turn necessitates changes in provisions for the public to view the thermal features. Spokesman Dan Hottle says such is the case inthe Upper Geyser Basin where the boardwalk has again been rerouted around some popular features. Hottle says about 300 feet of boardwalk between Scallop Spring and Sawmill Geyser has been replaced. Hottle says, “Sawmill Geyser is actually erupting to where it is throwing some hot water on visitors at certain points of the day.” Consequently, he says the boardwalk was routed about 30 to 40 feet away so that people won’t get wet and the boardwalk won’t get wet. Furthermore, he says the ground in one area was giving way and collapsing underneath it. Still, Hottle says the park was able to address the problem with minimal interruption to visitors’ abilities to enjoy the basin’s features. Despite the corrections, Hottle says the park did not have to close any areas of the boardwalk. Hottle says the boardwalks are actually built so that they lie on the surface of the ground rather than being anchored, enabling them to be easily shifted as the geologic changes dictate.