The valley forms the headwaters of the Santa Cruz River which flows south into Sonora, Mexico just east of the historic Lochiel townsite.

The San Rafael de la Zanja Land Grant lies in the valley center just north of Lochiel.

The Nature Conservancy purchased the former land grant ranch in 1998 and Arizona established the "San Rafael State Natural Area" in the valley in 1999 on the southern part of that property.

The State Natural Area is south of the land grant, and borders Mexico.

[citation needed] In 2008, the San Rafael Ranch headquarters was added to the National Register of Historic Places as the "San Rafael Ranch Historic District".