Personal income in 42 states fell in 2009, the Commerce Department said Thursday.

Nevada's 4.8% plunge was the steepest, as construction and tourism industries took a beating. Also hit hard: Wyoming, where incomes fell 3.9%.

Incomes stayed flat in two states and rose in six and the District of Columbia. West Virginia had the best showing with a 2.1% increase. In Maine, Kentucky and Hawaii, increased government benefits, such as unemployment insurance and Social Security, offset drops in earnings and property values.

Nationally, personal income from wages, dividends, rent, retirement plans and government benefits declined 1.7% last year, unadjusted for inflation. One bright spot: As the economy recovered, personal income was up in all 50 states in the fourth quarter compared with the third. Connecticut, again, had the highest per capita income of the 50 states at $54,397 in 2009. Mississippi ranked lowest at $30,103.

Write to Sara Murray at sara.murray@wsj.com