According to US Government estimates domestic marijuana production has increased ten fold over the last 25 years from 1,000 metric tons (2.2 million pounds) in 1981 to 10,000 metric tons (22 million pounds) in 2006. The ongoing proliferation of marijuana cultivation places it beyond the scope of law enforcement capabilities to control and reduce the availability of marijuana to teenagers and young children under existing public policy.
Using conservative price estimates derived from federal surveys, domestic marijuana production has a value of $35.8 billion, more than corn and wheat combined, easily making it America’s largest and most lucrative cash crop.
Based on production estimates derived from marijuana eradication efforts from 2003 to 2005 marijuana is the top cash crop in 12 states, one of the top 3 cash crops in 30 states, and one of the top 5 cash crops in 39 states. The domestic marijuana crop is larger than Cotton in Alabama, larger than Grapes, Vegetables and Hay combined in California, larger than Peanuts in Georgia, larger than Tobacco in both South Carolina and North Carolina, larger than Hay, Tobacco, Corn and Soybeans combined in Kentucky, and larger than the top ten crops combined (Soybeans, Hay, Cotton, Corn, Tobacco, Vegetables, Wheat, Cottonseed, Sorghum and Apples) in Tennessee.
Illicit marijuana cultivation provide considerable unreported revenue for growers without corresponding tax obligations to compensate the public for the social and fiscal costs related to marijuana use.
As America’s federal, state, and local governments strive to fund important services such as transportation, education, law enforcement and homeland security untaxed and unregulated domestic marijuana cultivation and distribution remains both an increasing challenge to policymakers and an untapped source of revenue for legislatures.
Twenty five years of aggressive law enforcement, led by the Drug Enforcement Administration’s (DEA) Domestic Cannabis Eradication/Suppression Program (DCESP), underscore the government’s inability to control marijuana cultivation and marijuana use in the United States. From 1982 to 2005 DCESP has eradicated over 103 million cultivated marijuana plants, an average of over 4 million plants per year. 
Contemporary marijuana policy is typified by the DCESP program, particularly through its attempt to suppress marijuana use and cultivation, a word that literally means to put an end to the activities of a person or body of persons; to do away with by authority; to abolish, stop the practice, to vanquish or subdue; crush; to reduce or eliminate.  The DCESP has been unable to achieve any of these objectives with regard to marijuana cultivation; indeed under current policies marijuana cultivation has thrived in the United States.
Three ‘tip of the iceberg’ revelations over the last 25 years indicate the lack of success of this policy of suppression.
1) In 1982 the DEA’s report on the DCESP program noted that “the program shows that in 1982, 38% more domestic marihuana (sic) has eradicated than was previously believed to exist.” 
2) In 2002 the National Survey on Drug Use and Health revised its data collection procedures and increased their estimate of annual marijuana users from 21.1 million (as reported in the 2001 survey results) to 25.7 million. 
3) After reporting from 1998 to 2000 that domestic marijuana production was 3,500 mt (7.7 million pounds)  the Office of National Drug Control Strategy reported in February 2003 that “more than 10,000 metric tons [mt] of domestic marijuana and more than 5,000 mt of marijuana cultivated and harvested in Mexico and Canada— [is] marketed to more than 20 million users.” 
This latest estimate of domestic marijuana production in excess of 10,000 mt was published in several government reports.
The 2002 International Narcotics Control Strategy Report (INCSR), issued by the US Department of State on March 1, 2003, stated:
“Marijuana production and consumption is a serious problem in many countries—including in the United States. More than 10,000 metric tons (MT) of domestic marijuana and more than 5,000 metric tons of marijuana is cultivated and harvested in Mexico and Canada and marketed to more than 20 million users in the United States. Smaller quantities of marijuana are also produced in Colombia, Jamaica, Paraguay and other countries.” 
The 2003 INCSR, issued on March 1, 2004, repeated this estimate:
“Cannabis (marijuana) production and consumption is a serious problem in many countries—including in the United States. More than 10,000 metric tons of domestic marijuana and more than 5,000 metric tons of marijuana is cultivated and harvested in Mexico and Canada and marketed to more than 20 million users in the United States. Colombia, Jamaica, and Paraguay also export marijuana to the U.S.” 
The 2005 report also included the identical claim:
“Cannabis (marijuana) production and consumption is a serious problem in many countries—including the United States, where it is by far the most widely used illicit drug. More than 10,000 metric tons of domestic marijuana and more than 5,000 metric tons of marijuana cultivated and harvested in Mexico and Canada is marketed to more than 20 million users in the United States. Colombia, Jamaica, and Paraguay also export marijuana to the U.S.” 
This estimate was also reported to the United Nations and circulated to the international community as this country’s official estimate in both the UN’s 2003 report on “Global Illicit Drug Trends” and their 2004 “World Drug Report.”
“Annual production of marijuana in the USA was estimated by the US authorities to amount to more than 10,000 [metric] tons in 2001/2002.”  
The source of this estimate of domestic marijuana production was the Marijuana Availability Working Group assembled by the Office of National Drug Control Policy (ONDCP); their 10,000 mt estimate of domestic marijuana production is explained in a December, 2002 report on “Drug Availability Estimates in the United States” The same estimation method has been previously used by this analyst in prior reports on domestic marijuana production over the last twenty years.   The MAWF estimates are also reported in a report on “Marijuana Availability in The United States and Its Associated Territories” by the Federal Research Service of the Library of Congress . The following excerpts from the Federal Research Service report provide an overview of domestic marijuana production in the United States:
“The MAWG calculated a speculative estimate of domestic marijuana production by applying three hypothetical seizure rates to domestic cannabis eradication figures. Based on the federal seizure of 1,215 metric tons of marijuana in 2001, the MAWG estimated the street availability of marijuana in 2001 to be between 10,000 and 24,000 pure metric tons.”
“The data reviewed for this survey suggest that the street availability of marijuana is more likely closer to the figure of 24,000 metric tons than it is to 10,000 metric tons”. Pg 1-2
“At most, U.S. authorities are able to seize only about 10 percent of marijuana, and most of this amount is from foreign sources of supply.” pg 3
“Whether cultivated indoors or outdoors, most domestically produced marijuana is intended for sale and use in the local area. Some of the marijuana produced in the high-production states (Alabama, Alaska, California, Florida, Hawaii, Kentucky, Oregon, and Tennessee) undoubtedly is transported to other areas for sale.”
“Indoor growing operations are becoming a large-scale problem. According to 2000 DCE/SP statistics of the DEA, the five leading states for indoor growing activity were California, Florida, Oregon, Washington, and Wisconsin. This listing differs slightly from the Bureau of Justice statistics, which lists the five leading states for indoor growing activity as California, Washington, Florida, Texas, and Alaska. These states do not necessarily have the most cannabis, but they may have the most, or the most effective, eradication programs.” Pg 11-12
The ONDCP (Office of National Drug Control Policy) tasked the Marijuana Availability Working Group (MAWG) with developing a methodology for making a reliable estimate of the amount of marijuana available in the United States annually. The MAWG, made up of members of various federal agencies, labeled its two-part methodology the Marijuana Availability Model (MAM). Using its MAM, the MAWG calculated a speculative estimate of domestic marijuana production by applying three hypothetical seizure rates to domestic cannabis eradication figures. In calculating the availability of domestically produced marijuana, the MAWG relied on cannabis eradication statistics along with plant yield estimates. Pg 22
Although the quantity of domestically produced marijuana available in the United States in 2001 was unknown, the MAWG calculated—on the basis of cannabis eradication figures and potential yield per cannabis plant—that the estimated figure was between 5,577 and 16,731 metric tons. Pg 22-23