At least 40 people were arrested and 30 homes and warehouses raided in an extensive marijuana growing operation raid by Colorado law enforcement Thursday morning.

All the locations raided were tied to a single pot growing operation, and most were in the Denver area, police told CBS 4. The suspects arrested in the raid came to Colorado from Texas to buy homes for the purpose of growing marijuana and shipping it out of state to be sold, CBS Denver reported.

SEE ALSO: Pennsylvania to become the 24th state to legalize medical marijuana

What DEA agents pulled from an illegal grow in Denver. Source says several raids happened targeting pot trafficking pic.twitter.com/jjJ2WaOKOc — Jason Gruenauer (@JGonTV) April 14, 2016

As many as 300 marijuana plants were found at a single home, along with a cache of pot growing equipment, requiring assistance from the Colorado National Guard to be cleared away.

At another home, police were forced to use tear gas to force out a suspect who had barricaded himself inside during the raid.

The sting was the result of a more than year-and-a-half long investigation by the DEA and local authorities into marijuana growing operations in Colorado. Though the consumption and sale of medical and recreational marijuana is legal in the state, the operations targeted by the raid were not, according to CBS 4.

Have something to add to this story? Share it in the comments.