For the area around Albany and Corvallis, you can find bus information at

https://cwride.org/

For the rest of Oregon, there are bus lines available at

https://www.greyhound.com/en 

For train lines to some places in Oregon at 

https://www.amtrak.com/home 

Find transportation to the Oregon State Fair from Albany Oregon using the CW Ride website:

https://cwride.org/