From the National Park Service website:

Although nothing of the original operation remained at the time of designation, a National Historic Landmark plaque commemorated the site of the First Pacific Coast Salmon Cannery Site. The company site consisted of a scow anchored on the west bank of the Sacramento River, directly opposite from the City of Sacramento's K Street. It is believed that the brothers resided on a cabin located on the shoreline. During the nineteenth century the barge was lost and numerous floods altered the appearance of the riverbank. The plaque is no longer extant and the riverbank's appearance has changed through the site's development as a park by the City of West Sacramento. Consequently, the site's designation as a National Historic Landmark was withdrawn on July 14, 2004 by the Secretary of the Interior.

You can read about this significant but short-lived enterprise at the website of the National Historic Landmarks Program.