Northumberland County is in Alleghenies & Valleys Pennsylvania. Of the 67 counties in the Keystone State, Northumberland County ranks 48th in terms of size (477 square miles). Northumberland County, Pennsylvania, has around 1,000 acres of farms for sale based on recent Land Network data. The combined market value of land for sale here was nearly $3 million. The average price of farms for sale in Northumberland County was $530,000. Farms for sale in Northumberland County sustain livestock including horses, cattle, sheep, pig and goats. Browse all Pennsylvania farms for sale on the Land Network to find the farm, cattle operation, hobby farm or other farm property that's right for your future commercial or individual needs.