Colorado became the first US state to legalize the commercial sale of cannabis in 2012, and stores opened for business on 1 January 2014.
In total, 59 marijuana firms filed tax returns on an estimated $14m in sales.
Overall, the state collected a total of $3.5m in marijuana taxes if medical marijuana firms are included.
The money is earmarked for youth prevention services, substance abuse treatment, and public health, according to a plan proposed by Colorado Governor, John Hickenlooper.
Many other US states are closely watching Colorado’s figures.
Washington state is set to introduce legal sales later this year.
Most of Colorado’s tax revenues came from firms around the city of Denver.
Recently, US President Barack Obama said marijuana was no more dangerous than alcohol, while cautioning both were bad decisions.
Nonetheless, he has instructed the Department of Justice to halt prosecutions of banks that do business with cannabis firms.
Currently, 20 US states, as well as Washington, DC, allow for the sale of medical marijuana.