Prosper is a historic community on the Coquille River, about 10 miles (16 km) west-southwest of Coquille and 3 miles (5 km) northeast of, and upstream from, Bandon, Oregon. The Coquille River drains a watershed of 677,760 acres (274,280 ha) on the western flank of the Oregon Coast Range, between the Coos River to the north and the Rogue River to the south. Much of the watershed downstream from Coquille sits atop the Coaledo Formation and its older counterpart, the Tyee Formation. These sediments were deposited in the Eocene epoch beginning some 50 million years ago. The Coaledo marks the southern end of the Coos Bay coal field, and nearly all the coal mined there came from the formation’s upper layer.

Early pioneers established several settlements downstream from Coquille. These included Riverton, a coal-mining town laid out in 1889; Parkersburg, where Captain Judah Parker built a sawmill and shipyard around 1876; and Randolph, a black-sand-mining camp where Adam Pershbaker had settled. When Randolph’s mining industry declined in 1892, Pershbaker moved about a mile downstream and founded Prosper around a sawmill he built there. In 1893 he established the town’s post office and became its first postmaster; the office ran until June 1928. Emil Heuckendorff soon added a second shipyard. The name was apparently chosen in hopes the locality would prosper. By 1915 the population had reached 500, supported by two salmon canneries and two shingle-and-saw mills, with passenger boats running three times daily, downstream to Bandon and upstream to Coquille.

The Coquille’s tidal effect reaches upstream to Myrtle Point, some 28 to 30 miles from the river mouth. Saltwater intrusion across the bar was once minor, a 1979 survey found summer channel salinity stayed above five parts per thousand no farther than about river mile 7 (11 km) at low tide, and about river mile 14 (22.5 km) at high tide. But traces of salinity now sometimes appear just a few miles downstream of Coquille, affecting mills and other facilities that depend on freshwater intakes to avoid rusting or damaging equipment. Saltwater intrusion caused by the inland advance of saline water into freshwater bodies, is a growing problem for coastal rivers, and is generally driven by rising sea levels, reduced freshwater flows and human factors such as groundwater pumping and land-use change. Read more here and here. Explore more of Prosper and Coquille River here: