Cheryl Petska, the first woman to become a Virginia state trooper and a representative of the state police at the state fair and in promotional films, was fired at midnight last night.

The 31-year-old Petska received a letter stating she was being fired for "insubordination" -- her refusal of a two-week tour of duty in the coalfields of southwest Virginia following the recent coal strike.

But Petska claims she was given only 48 hours notice of her new assignment and was unable to find anyone on such short notice to babysit her two children, Tracy, 10, and Attorney, Joseph Duvall.

Major C. S. Johnson, the state police field supervisor who wrote the letter of dismissal to Petska, acknowledged last night that she had been fired, but he declined commern on the specifics of the case.

"It's a perosnnel matter. It's between the department of the state police and Mrs. Petsk. The matter is still pending and there are other avenues -- the right of appeal," said Johnson.

Duvall said he will file a demand for a hearing with the state police superintendent in Richmond on Tuesday and will ask that Petska be reinstated. It the stake police fail to reinstate her, he'll take the matter to court, he said.

Petska, who is stationed at Fredericksburg and live there, had been assigned to the coalfields to guard against possible destruction of property around the mines in the wake of the heated four-month-long United Mine Worker's strike. The strike ended March 31 but state police continued to assign offecers there to prevent sporadic violence.

The coal fields are "an 8-hour drive, 400 miles from home," according to Duvall. He claims that the state police had known that troopers would be needed to guard the coal fields for months and could easily have given his client enough time to find someone to care for her children. Other state police divisions such as Division 2 -- give more advance notice, he claims. Petska served in Division 1.

Petska's husband, Mark, also is a state trooper, an undercover anrcotics agent who is called frequently on out-of-state assignments on a moment's notice, thus leaving the children in ner care.

Usually Petska's mother stays with her children, but the Dec. 1 order to go to the coal fields on Dec. 2 was such short notice that Petska did not even ask her mother to babysit the children, according to Duvall. Her mother lives in Charlottesville.

"Troopers have private lives too. They have children. If Division 2 can plan for it, why can't Division I?" asked Duvall.

Duvail claims his client has had a commendable career with the state police since she joined them on Oct. 15, 1976 -- 500 arrests in the first year.

He points to the fact that Petska who makes $12,000-a-year was filmed in a television studio as part of a state police promotional film that may be aired soon.

She also represented the police at the state fair for 10 days this year, said Duvall, and "She was more or less on display."

Petska's attorney claims that though there are now a few other women troopers -- four out of more than 1,000 troopers -- the male offices still resent having women troopers and make little or no allowance for lthe problems they face.

According to Duvall, Petska said "It deflates their ego to have a woman. The department is designed and made for men and it hasn't changed any."

Maj. Johnson, who wrote the letter of dismissal, said that he "presonally has not one thing against women troopers. We do everything we can to be as fair as we can be with all troopers, male or female."

Petska wants to get her job back, and believes she has done well at it thus far. She does not know what she will do if she is not reinstated, and recalls that "23 weeks of training were mentally and physically pure hell," according to Duvall.

She had a hired a housekeeper curing that period to watch her two children, said Duvall.