HELENA – A crowded Republican primary field vying for Montana governor in 2012 is growing even larger, with state Sen. Jeff Essmann joining an already large field.

Two others, a science fiction author and an anti-wolf activist, joined the list of GOP candidates seeking to replace Democratic Gov. Brian Schweitzer, who is leaving office because of term limits.

Essmann, from Billings, became the eighth GOP candidate Tuesday night when he announced with a promise to reform the state tax code to spur investment, make public the state checkbook and establish a “hotline” in the governor’s office for those having problems getting through government red tape.

Like other GOP candidates, he promised to lure higher-paying jobs and promised to be a state leader who would stand up to the Obama administration.

Essmann is perhaps best known for leading the Legislature’s crackdown on medical marijuana.

Democrats have two candidates, including state Attorney General Steve Bullock.

Earlier this week, Republican Bob Fanning of Pray, known for opposing the reintroduction of wolves and fighting their continued protection, began publicizing his plans to run. Real estate investor and self-published science fiction writer Drew Turiano filed paperwork Monday that would allow him to start raising money for a gubernatorial bid.

Better-known Republicans in the race include former U.S. Rep. Rick Hill, who shot out of the gate late last year with plenty of support from party insiders and a strong fundraising lead; former state Sen. Ken Miller of Laurel, who is trying to rally tea party support with his cadre of green shirt-clad supporters; and former state Sen. Corey Stapleton of Billings.

Consultant Neil Livingstone, frequently seen on cable television as a security and terrorism expert, has moved back to Helena from Washington, D.C., to mount a campaign with former Navy SEAL and current Whitefish state Sen. Ryan Zinke as his running mate for lieutenant governor.

Chouteau County Commissioner Jim O’Hara is trying to distinguish his candidacy with hand-painted billboards in every county featuring a rendition of the local county courthouse.

Fanning, a former businessman now known for leading the Friends of the Northern Yellowstone Elk Herd group, said he will raise enough money to be competitive and promote his credentials as a fiscal and social conservative with a libertarian streak.

Turiano, who worked on the unsuccessful 2008 U.S. Senate campaign of Mike Lange, said he hopes to be the most conservative in the crowded field. He said he opposes any type of abortion, even in cases of rape, and actively supports states nullifying federal laws they oppose.

Bullock, the Democrat, has been stockpiling money and using his position as the state’s attorney general to gain attention.

He is so far only challenged in his party’s primary by state Sen. Larry Jent of Bozeman, who has lagged behind in fundraising and organizational support.