Built by William P. Kyne, who also built Bay Meadows Racetrack in San Mateo, California, the facility opened on September 14, 1946.
Opening with over 10,000 people in attendance, Portland Meadows made history as the first thoroughbred track in the nation to offer night time racing. This was made possible by use of a lighting system designed by General Electric which has been said has enough power "to light a four-lane superhighway from Portland to Salem, a distance of 40 miles."
Located in Portland, Oregon conveniently off of Interstate 5, Portland Meadows offers the heart pounding and pulsating action of live Thoroughbred Horse Racing.
The grounds are in Hayden Meadows near the Columbia River and are 16 feet (4.9 m) above sea-level.
In 1948, the track was closed due to the Vanport Flood. This flood destroyed the town of Vanport City, Oregon, and resulted in roughly $250,000 worth of damage to the track.
On April 25, 1970 a fire burnt the grandstand to the ground. Fortunately the blaze took no lives, human or equine, but it did end the meet.
In 1971, the facilities was rebuilt and track reopened to a record crowd of 12,635. 
Thirty one years later, in 2001, Magna Entertainment acquired the racing license for Portland Meadows. Prior to the 2001-2002 meet, the racing surface was completely renovated. The Clubhouse level and Turf Club Restaurant were also refurbished and a new simulcast center was opened on the mainline level.
In 2003, Portland Meadows undergoes a series of improvements including the construction of a children's play area, upgrades in the paddock, gallons upon gallons of new paint throughout the building, new fencing and the inclusion of a grass apron. Among additional changes of significance are the live race days and an increase in handle. Since dropping Sunday racing and adding Monday matinees, there's been an increase of over 100 new simulcast outlets taking the Portland Meadows signal. 
Owned by The Stronach Group since July 3, 2011 and previously owned by MI Developments Inc. (MID) 2001.
Jerry performed here on
8/8/93 Jerry Garcia Band
5/28/95 Grateful Dead
5/29/95 Grateful Dead
1.)^"Portland Meadows". Geographic Names Information System, U.S. Geological Survey. 1980-11-28
2.)^Portland Meadows Web Site, Track History
3.)^Portland Meadows Web Site, Track History
4.)^Portland Meadows Web Site, Magna Ownership