Yamhill River lock and dam

Yamhill River Lock and Dam
Steamer Bonita in Yamhill Lock, September 24, 1900
Location of Yamhill River Lock and Dam in Oregon
Country	USA
Location	Lafayette, Oregon
Coordinates	45°13′50″N 123°06′15″W / 45.23056°N 123.10417°W / 45.23056; -123.10417
Purpose	navigation
Status	Decommissioned
Construction began	1898
Opening date	September 22, 1900
Demolition date	circa 1965
Construction cost	$72,164.83
Operator(s)	Corps of Engineers
Dam and spillways
Type of dam	Timber-crib stone-filled
Impounds	Yamhill River
Height (foundation)	26 feet (7.92 m)
Length	125 feet (38.10 m)
Width (base)	30 feet (9.14 m)
Spillways	one
Spillway type	Stepped.
Reservoir
Maximum length	9 miles (14 km)
Maximum water depth	16 feet (4.88 m)
Yamhill River Lock and Dam
U.S. National Register of Historic Places
Lock walls and downriver entrance, May, 2009
Area	8 acres (3.2 ha)
Architect	US Army Corps of Engineers; Normile, Fastabend & McGregor
NRHP reference No.	91000799
Added to NRHP	June 21, 1991

The Yamhill River lock and dam was completed in 1900. It was built near Lafayette, Oregon, to allow better river transport on the Yamhill River from Dayton, to McMinnville, Oregon. While the Corps of Engineers had recommended against construction of the lock, it was built anyway, largely as a result of political effort by the backers of the project. For almost forty years prior to the lock construction there had been efforts made to construct a lock and dam on the Yamhill River.^[1]

The lock was a single-lift chamber 210 feet (64 m) long and 40 feet (12 m) wide, located on the west side of the river. The dam extended from the east bank of the river to the eastern lock wall, and when the lock gates were shut, acted to back up the Yamhill river and raise the water level sufficiently to allow ready steamboat navigation to McMinnville during the summer dry season. During the winter, the lock and dam were more of an obstruction than a navigational aid, as they were frequently overtopped by freshets and floods, sometimes as high as or higher than twenty feet above the lock walls.

The lock ceased to be used in any significant way soon after it was built. There was an upsurge in use of the river during the 1930s and 1940s primary for transport of logs. The lock continued in operation until the 1950s, when the U.S. government concluded that the little amount of traffic on the river no longer justified the expense.

The lock and dam were then turned over to Yamhill County. The county lacked the funds to maintain or restore the lock, and the dam, having been viewed as a barrier to spawning salmon, was eventually destroyed with use of explosives. The lock walls remain to this day. The lock keeper's residence, built at the same time, and now in private hands, also remains. A county park is nearby from which the lock structure can be viewed. Some other remains of the work, such as pilings, are also visible at low water.

While not particularly remarkable as an engineering project, the lock was one of only three lock and dam projects commenced in Oregon and indeed in all of the Pacific Coast states by the United States government during the 19th century.^[1]

The lock and dam are also representative of the results of local pressure for expenditure of funds from the national government for works of a local nature.^[1] A substantial portion of the project remains visible to this day, and has been said to be "one of the last tangible remnants in the Upper Willamette Valley of a time when river navigation played an important role in transporting freight and passengers."^[1]

The lock is sometimes referred to as the Lafayette Lock.^[1] The Lafayette Locks Park, maintained by Yamhill County, Oregon now occupies the site of the old lock and dam.^[2]