The average rent for the state rose 4.25% to $785. The Colorado Multi-Family Housing Rental and Vacancy Survey tracks vacancies and rental costs for 21 housing markets outside of the Denver metro area. That means a renter needs an annual income of $31,500, or $15.15 per hour, to afford the average rent.

Both the ski resort communities of Aspen and Summit County showed vacancy rates of 4.4%, the highest since Von Stroh started the survey in 1995.

Tom Hart, director of the Colorado Division of Housing, says he thinks that the rises are due to the terrorist attacks on Sept. 11 and the subsequent drop in tourism and travel. Hart says that ski resorts appear to be expecting fewer tourists this year. That means the ski resorts will hire fewer people. And retailers and restaurants also will need fewer people.