First human environment interaction on Columbia river?

Answer 1

It is believed that North America was first colonized around 15,000 to 17,000 years ago with a rapid colonization of the West Coast of the USA and undoubtedly along the Columbia River, although the archeological evidence shows people along the river around 10,000 years ago.


Image from Wikipedia of fishing activities at Celilo Falls on Columbia River. Photo taken in the 1950's and is part of the USACE archives and is in the Public Domain.
http://en.wikipedia.org/wiki/Celilo_Falls,

In 1792, Captain Robert Gray started exploring the mouth of the Columbia.
In 1805, Lewis and Clark traveled West, including a period of traveling along the Columbia river and eventually arriving at the mouth of the Columbia and the Pacific Ocean.

As early as the 1850's, logging was starting along the Columbia River, and the river was used as a means to transport logs and log rafts to the mills.

Here is an excellent history of the USACE work on the Columbia River:
http://140.194.76.129/publications/misc/un24/

In 1865 Portland began dredging in the Columbia.

Around 1876 work was started on canals around the Cascade Rapids and the Celilio Falls near the Dalles.

Around 1885 the Federal Government started construction of Jetties in Astoria.

While technically not on the Columbia, the dams and hydroelectric power generation on the Willamette River, Willamette Falls in Portland was started in 1888.
http://en.wikipedia.org/wiki/Willamette_Falls
http://willamettefalls.org/Hist/Elec

1932 the Rock Island Dam became the first dam on the Columbia River, followed by the Bonneville dam in 1938 and the Grand Coulee dam in 1941.
http://www.ccrh.org/river/history.htmhttp://en.wikipedia.org/wiki/Columbia_River

Work on the Dalles Dam was begun in 1952, and completed in 1957 as Celilo Falls (above) was submerged in March 10, 1957, and along with it one of the oldest continuously active human settlements in North America.