A strike by state workers spread Friday as employees at Montana's home for the mentally retarded and its mental hospital joined state troopers and thousands of others on picket lines.

The walkout by 4,000 state employees included road crews. Weather forecasters called for up to 4 feet of snow.About 400 National Guard troops were deployed to the Montana Developmental Center and the state hospital. Some 300 guardsmen already are stationed at the Montana State Prison, the Veterans Home and other institutions where workers walked out Thursday.

The new strikers walked off their jobs promptly at 10 a.m., when a restraining order expired. Guard troops were deployed shortly afterward.

Bob Anderson, administrator of the Institutions Department special services division, said all admissions and evaluations of patients at the home for the mentally retarded, as well as daily activities, were halted.

"Families may want to come and take some patients home for a couple of days," Anderson said.

Jane Edwards, Montana State Hospital superintendent, said strikers include aides, housekeepers, psychologists, social workers and therapists. Registered nurses at the state hospital, where 290 patients get care, are honoring the picket line, she said.