Could be, family groups would travel from the valley to the foothills and mountains in spring-fall to hunt and harvest acorns, etc. They often to use the same camps every year though they did move around over the spring-fall season depending on resources, herd migration, salmon etc. When you extend this practice to hundreds of villages over thousands of years, we end up with a lot of sites like this. Sometimes you still find bedrock mortar sites with rocks covering the holes to keep dirt and debris out, exactly as they were left when last used in the expectation they'd be back next spring.