Boise, Idaho is 68% larger than Salem, Oregon.
Area: 207 km2 calculated
Boise is the capital and most populous city of the U.S. state of Idaho, as well as the county seat of Ada County. Located on the Boise River in southwestern Idaho, the population of Boise at the 2010 Census was 205,671, the 99th largest in the nation. Its estimated population in 2013 was 214,237. Wikipedia
Area: 123 km2 calculated
Salem is the capital of the U.S. state of Oregon, and the county seat of Marion County. It is located in the center of the Willamette Valley alongside the Willamette River, which runs north through the city. Wikipedia