Sacramento National Wildlife Refuge Complex — the main refuge south of Willows is one unit of a larger complex that includes several refuges spread across the Sacramento Valley. Exploring more than one unit on the same trip gives a fuller picture of the flyway and its extraordinary scale.
Chico (45km north) is a university town with far more life than you'd expect in this stretch of the valley. Bidwell Park is one of the largest municipal parks in the United States, with good hiking and swimming holes. The downtown has decent restaurants, bookshops, and a lively café culture.
Orland and Black Butte Lake (20km north) offers fishing, boating, and outdoor recreation in the foothills just west of I-5. A straightforward half-day trip for those wanting to get off the highway.
Red Bluff (60km north) is the gateway to Lassen Volcanic National Park, one of California's less-visited national parks with active hydrothermal features, hiking trails, and dramatically volcanic landscapes. Worth a full day or overnight if you have the time.