By 1900, families who had taken up residence in South Slough had substantially altered the landscape to accommodate agricultural, transportation, and logging needs. Marshes were separated from the tides with earthen dikes and drained by ditches. Tide gates kept out salt water and provided drainage of fresh water. The dikes also served as roadways and, with culverts, as bridges across small streams or marshy areas. Almost all (90%) of the former tidelands around the edges of the Coos estuary have been diked or filled to accommodate transportation routes and to create flat land for building and agriculture.
By the 1960s, many tide gates along South Slough began to fail and have been allowed to deteriorate, while the earthen dikes are gradually eroding and have breached in some spots. As a result, former pasture lands are in various stages of reversion from uplands and freshwater wetlands to estuarine habitats. Creeks in the shallower parts of the South Slough watershed were dredged during the early to mid-1900s for logging and other transportation needs. Some creek banks are deeply scarred by splash-damming, the practice of damming and then suddenly releasing a volume of water to float logs downstream. Surplus dredge spoils were piled in the slough, and remain as small islands.
Logging and Mining
Logging and associated road building has produced the most marked changes in the uplands of the South Slough watershed. All timber in the drainage has been cut at some time, and most of the watershed continues to be managed for commercial forest purposes by public and private owners. Some of the more evident changes caused by logging include a number of clearcuts in various stages of recovery, compacted dirt roads, and remnants of trestle railroads. Parts of the shoreline and segments of Winchester Creek are lined with pilings which formerly supported docks or small donkey engine railroads for log hauling. The last large commercial cuts inside Reserve boundaries were made in the early 1970s. A small private inholding, subsequently purchased by the Reserve, was logged in 1992.
A small coal mine operated in the southern portion of the South Slough drainage during the late 1800s, but was later abandoned.
Most of the pasturage along South Slough was abandoned in the 1930s, although cattle were grazed on one parcel within the Reserve until the late 1980s. Cattle continue to be grazed just south of the Reserve along South Slough’s main tributary, Winchester Creek.
Fishing and Acquaculture
Commercial and sport fishing, which occur just outside the estuary, are an important element of the local economy. Commercial fishing supports a number of seafood processing plants in Charleston. The Oregon Department of Agriculture leases out several acres of state-owned submerged lands in the Coos estuary and South Slough for commercial oyster cultivation. The presence of the commercial oyster industry encourages maintenance of excellent water quality, and recreational clam harvesting is also common.