It is located south of Forest Grove and north of the city of Gaston on Oregon Route 47 in the Portland metropolitan area.

[4] In 1850, Parsons built a grist mill along the Tualatin River near what later became Dilley on the land claim of William Owen Gibson.

[4][5] Gibson settled his claim in 1847, and built the log cabin used for Tabitha Moffatt Brown’s orphan school that later became Pacific University.

[5] A flour mill was added nearby in 1863, and Joseph Gaston’s West Side Railroad reached the area in 1872.

[5] Other businesses in the community in the early years were a barber shop, general stores, ice warehouse, and a blacksmith among others.

[5] Other businesses at one time included a hotel, dance hall, saloons, machine shop, and a hardware store.

Dilley, classified as a populated place, sits at an elevation of 197 feet (60 m) above sea level.