Iron County Sheriff's spokesman Jody Edwards said Wednesday that officers -- tipped off by hunters -- have located at least two major grow areas composed of "very healthy, tall, robust marijuana plants."

Some of the plants towered to 8 feet high and had shafts 2 inches in diameter.

Edwards said it is clear that whoever grew the pot used a hybrid seed that allows marijuana to thrive, even in weather that is not normally conducive to growth.

The canyon area, located at about 7,500 feet elevation, gets cool at night, Edwards said, adding that marijuana typically needs hot, humid weather at lower altitudes to flourish.

Officials have not yet estimated how many acres the pot farm encompasses, but Edwards said they needed to walk "quite a distance" to cover the entire area.

The find seems to be part of a trend in the southern Utah area lately.

In late July, officials found about 7,500 pot plants with an estimated value of $9 million in neighboring Washington County's Pine Valley area when some hikers reported seeing the marijuana.

One week earlier, highway patrol seized 210 pounds of pot in a traffic stop near Monticello in southeast Utah's San Juan County.

In late June, five Mexican nationals were arrested in Kane County and indicted for drug trafficking, cash smuggling and illegal possession of firearms after authorities found $49,000, five guns and a large bag of pot.

Also in June, federal investigators found 30 vacuum-packed bundles of marijuana, totaling 37 pounds at St. George Airport.

And in January, the Washington County Sheriff's Office arrested an Ivins man after police said they found illegal drugs, guns and drug paraphernalia in his car and home.