During his career the region between Snoqualmie Pass and the North Cascades, where he did most of his work, was frequently updated with new maps showing the results of ongoing USGS and Forest Service surveying and exploring. This made it possible for Sylvester's place names to become well established and used. His prolific place naming was due in part to Gifford Pinchot, the first Chief of the Forest Service. During the Pinchot era national forests were relatively new and often largely unmapped and lacking in place names. In order to better protect the forests from wildfire it was necessary to have names for natural features and detailed maps so that fires could be located by name and fire fighters sent to the right places. In regions like the Wenatchee National Forest there were a large number of unnamed features. Significant parts of the mountains were essentially unexplored, except by Native Americans and, in some areas, prospectors, who tended to be secretive about their discoveries. Thus Sylvester found himself exploring and mapping a large region with relatively few established names and what amounted to a mandate to bestow names.