Ellensburg sits at the junction of I-90 and I-82, about 105 miles east of Seattle. The drive takes 1 hour 45 minutes in good weather over Snoqualmie Pass, longer in winter when the pass closes for chain control. Seattle is the closest major airport (SeaTac); the smaller Yakima airport is 35 minutes south.
There is no passenger rail service. Greyhound runs a couple of buses a day from Seattle and Spokane; Bellair Charters operates a direct shuttle from SeaTac to Ellensburg and the CWU campus. In town everything is walkable; the bus system is basic and the streets are dead simple to navigate by car.