The crossword solution for the term BIG BASIN is TUB. Big Basin Redwoods State Park is a state park in the Santa Cruz Mountains of California, located near Boulder Creek. It is the oldest state park in California and contains over 18, 000 acres of old-growth redwood forests. The park is home to many species of wildlife, including the endangered marbled murrelet, and is popular for camping, hiking, and fishing. The park also features a large number of natural pools, or 'TUBS, ' which are formed by the erosion of the surrounding landscape.