Markham, WA has a population of 227 and is the 23,877th largest city in the United States. The population density is 203 per sq mi which is 110% higher than the Washington average and 125% higher than the national average. The median age in Markham is 63 which is approximately 68% higher than the Washington average of 38. In Markham, 87% of the population over 15 years of age are married, 88% speak English and 0% speak Spanish. 92% of Markham residents were born in Washington, 8% were born out of state, 0% were born outside of the United States and 0% were foreign born.