PORTLAND, Ore. (Reuters) - The first month of taxable commercial sales of recreational marijuana in Oregon generated nearly $3.5 million in tax revenues, far exceeding projections, the state Department of Revenue has reported.

Displays at Shango Cannabis shop on first day of legal recreational marijuana sales beginning at midnight in Portland, Oregon October 1, 2015. REUTERS/Steve Dipaola

Oregon’s marijuana tax receipts from January also surpassed the first-month tallies from recreational cannabis sales in Colorado and Washington state, the first two states to legalize general commercial distribution of pot for adults.

Colorado collected $2.9 million in taxes when recreational sales launched there in January 2014, a sum that included revenue from both recreational and medical cannabis purchases.

Washington’s recreational industry, which started slow with just 18 stores licensed to sell pot, yielded $1 million in tax revenue when it debuted in August 2014.

By comparison, Oregon’s 300 licensed cannabis retailers sold $13.9 million worth of marijuana in January, generating $3.48 million in taxes, according to a revenue report issued on Thursday.

The stronger-than-expected sales may have stemmed in part from the state’s gradual approach to pot taxation, allowing more time for businesses to get established.

Adults over 21 have been permitted to buy marijuana from dispensaries in the state since Oct. 1, 2015, and for the first three months those retail sales were untaxed. A 25 percent sales tax went into effect on Jan. 1, although it is waived for cannabis buyers with a medical card.

Oregon’s Liquor Control Commission, charged with regulating the drug, had forecast annual tax revenues of about $8 million during the first two years of legal recreational pot sales.

Although tax structures vary across the three states where pot sales are currently legal, all have earmarked funds for similar programs - schools, drug and alcohol counseling, and law enforcement.

Cannabis use remains classified as an illegal narcotic under U.S. federal law, putting the national government at odds with a growing number of states moving to legalize cannabis for medical purposes, recreational use or both.

In Alaska, where voters legalized recreational marijuana in 2014, regulators expect stores to open by the end of this year.

Voters in the District of Columbia have legalized recreational pot as well, but a congressional budget bill passed last year bars sales of the drug until 2017 or later.