diamond deserts and redwood forests could net a sizable amount of cash if we ever decided to sell it .
all the land in the lower 48 states was worth a combined $ 23trillion in 2009 , combination of tax and real estate data in a paper published by the commerce department as revealed .
a map of the us by county shows areas with land values from $ 73,000 to $ 3.35 million per acre in dark blue and land less than $ 23trillion .