Final answer:
A natural resource is an item obtained from nature that can be used to produce goods and services. Based on the description, the Once-ler could have found beaver as the important natural resource in the new region.
Step-by-step explanation:
A natural resource refers to items that are obtained from nature and can be used to produce goods and services. These resources are found in nature and have not been manufactured or altered by humans. An example of a natural resource is oil, which was initially seen as a nuisance until its refining process was discovered, making it valuable for various purposes.
The Once-ler, in the story, came across a new region and found an important natural resource, which is not explicitly mentioned. However, based on the description, the natural resource could be interpreted as beaver, as the story mentions a stream of water, great half-submerged mounds of brush and sticks, and old and new gnawed circles at the base of the cottonwoods, indicating the presence of beavers in the region.
The Once-ler's feelings about the region and the natural resource he found are not explicitly stated in the question or the provided information. Therefore, we cannot determine his exact feelings based solely on the given context.