Portland, Oregon is 3.5% larger than Las Vegas.
Area: 363 km2 calculated
Las Vegas, officially the City of Las Vegas and often known as simply Vegas, is the most populous city in the state of Nevada and the county seat of Clark County. Wikipedia
Area: 376 km2 calculated
Portland is the largest city by population in the U.S. state of Oregon, near the confluence of the Willamette and Columbia rivers. Wikipedia