The Walnut Grove Branch of the Southern Pacific was built to compete for agricultural trade from the rich Sacramento Delta area. Reclamation of the area was booming around the turn of the century (1900), and a route south from SP's Sacramento base of operations would compete well and provide a new mainline to the San Francisco area. The line was completed to Walnut Grove in 1912, and extended to its ultimate terminus at Isleton in 1929. The right-of-way passes through the outskirts of downtown Sacramento, suburban sprawl, and lastly agricultural land. Traffic was almost exclusively agricultural goods from packing plants and transshipment points in the various small towns that line the Sacramento River along this route. The line is unique in that it is built almost entirely on levees, often perched above the Sacramento River or an adjoining slough. The line was in service to Isleton until a 1971 flood, and to Hood until 1977.
Today (2004), tracks are in place along much of the right of way north of Hood to the Sacramento City limits. In Hood and Locke, the remnants of spurs to riverside cold storage facilities and warehouses are visible through the pavement alongside state highway 160. Locke is a historically significant "Chinatown" of the Delta, where many descendants of transcontinental railroad laborers settled. The bridge over the channel separating Walnut Grove and Locke is in place (see photo) and in Isleton, the rail loading facilities at a riverside storage silo are clearly visible. To see the Isleton branch, State Highway 160 and the associated river roads on the east side of Sacramento provide the most access. Abandoned rails still cross Hood-Franklin Road approximately 1/2 mile east of Hood, and the junction of the spur to Hood is clearly visible at this location (Hood Junction in the timetable), although much of it is being overtaken by vegetation. Between Hood and Locke, the right of way is now a private gravel road. Track is still in place south of Baths until Hood Franklin Road, although much of it is being overtaken by vegetation.
The State of California acquired substantial portions of the right-of-way in conjunction with the development of the California State Railroad Museum. It operates excursions on the northernmost few miles within the City of Sacramento. It may be extended further down the line in the future.