What is the half way point between Spokane WA and Las Vegas NV?

The halfway point between Spokane, Washington and Dallas, Oregon is between Arlington, Oregon and Boardman, Oregon.

The total mileage is 413 miles, so halfway is 206.5 miles which puts in between Arlington and Boardman.

On I-84 there is an exit ramp to Heppner Hwy #74 which is 206 miles from Dallas, Oregon and 207 miles from Spokane, a perfect halfway point.