The Santa Maria River is formed by the confluence of the Sycamore and Kirkland Creeks, about east of the community of
Bagdad. From the confluence, the river flows in a generally southwesterly direction through the rugged
Arrastra Mountain Wilderness area (
Poachie Range–
Black Mountains). The river accepts a number of smaller, intermittent streams throughout its length. The river joins the
Big Sandy River to form the Bill Williams River just upstream of Alamo Lake. During periods of heavy rainfall, the lake may extend beyond the confluence point, during which period the Santa Maria empties directly into the lake rather than joining the Big Sandy River. The total length of the river is approximately , of which are considered
perennial stream. The remainder is
ephemeral and runs only during periods of heavy rain. ==See also==