Multnomah County, OR vs Clark County, WA
Neighbouring counties across the Oregon and Washington state line, compared on population, size, income and housing. They share 33 mi of border.
Multnomah County
Oregon
Clark County
Washington
Both outlines are drawn at true relative size. Multnomah County spans about 78.1 km at its widest.
Side by side
| Measure | Multnomah County | Difference | Clark County |
|---|---|---|---|
| Population | 795,391 | +49.5% | 532,119 |
| Change since 2020 | -2.6% | -7.9 pp | 5.3% |
| Land area | 431 sq mi | -31.4% | 628.5 sq mi |
| Population density | 1,845 per sq mi | +117.8% | 847 per sq mi |
| Median household income | $88,766 | -9.0% | $97,536 |
| Median home value | $552,700 | +5.7% | $522,900 |
| Median age | 38.7 | -1.0% | 39.1 |
| Households | 349,803 | +78.5% | 196,017 |
| Housing units | 371,179 | +81.6% | 204,375 |
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026; US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. The difference column is computed here: the first county's figure against the second, expressed as a percentage of the second. The change-since-2020 row is the exception: two growth rates differ in percentage points (pp), not percent. Retrieved 30 August 2026.
What the numbers say
- Multnomah County holds about 1.5 times the population of Clark County: 795,391 against 532,119.
- Clark County covers more ground, at 628.5 square miles against 431.
- Multnomah County is the more crowded of the two, at 1,845 people per square mile against 847.
- Median household income is higher in Clark County, by 8,770 dollars a year.
- Since 2020, Multnomah County has shrunk by 2.6% and Clark County has grown by 5.3%.
- They share 33 mi of common border, which the Census Bureau publishes in its county adjacency file and which almost no other county reference presents.
Full pages
Want a different pair? Compare any two of the 3,144 US counties.
Rebuilt from source data 30 August 2026. How these figures are produced.