Montgomery County has taken a leaf from history and formed its own Conservation Corps, a job training program for unemployed youths who also are performing needed environmental preservation work. County officials introduced the program last week at the Brookside Nature Center in Wheaton.

The corps plans to hire 20 persons aged 17 to 22 each year to work on crews throughout the county. There currently are 10 openings.

Montgomery County Council members Neal Potter and Rose Crenca, speaking at the ceremony at the nature center, urged that the program be implemented by the state and federal governments, as was proposed in legislation sponsored by Maryland Sen. Charles McM. Mathias (R) last year. Crenca compared the county program with the national Civilian Conservation Corps of the 1930s.

Unlike other county youth programs that operate during the summer months, the corps is a full-time program. The federally funded Job Corps, training low-income youths for one to two years, does not operate in the county.

Conservation Corps members recently cleaned out about five tones of trash and debris, including 100 discarded auto tires, from the Northwest Branch stream in Wheaton and are laying wood chips on a trail at the Brookside center as part of an erosion control project.

The corps soon will begin to lay erosion-control water piping under a horse trail at the Wheaton Regional Center, said corps coordinator Debbie Shepard.

That type of work occasionally had been done by volunteers or summer youth groups, said corps director Richard Crane.

The wood chip-laying job at Brookside had been done in the past by the Boy Scouts as a summer project, said Joseph Callaway, a corps site supervisor. Callaway said that his crew will finish the task in about two weeks.

Earlier this year the state launched a summer Maryland Conservation Corps for disadvantaged youths, which was run by the state departments of employment and training and natural resources and the federal Summer Youth Employment Program. About 800 young people worked on 80 projects all over the state, except for Southern Maryland and the suburbs here.

Next summer, all counties will participate.

Meanwhile, the Montgomery corps ''will do some drudgery work,'' but they have not been hired to do strictly maintenance, Crane said. The assignments help the youths gain skills in a short time, so they can see the impact of their work, he said. At the outset, they are paid $3.35 an hour, the minimum wage.

Based on the old Robert W. Peary High School in Rockville, the corps is administered by the county department of family resources at the annual cost of $220,000, Shepard said.

Several corps members who have been in the program about two months said that they especially liked working outside.

''This is the first job I've had in a long time that I look forward to on Monday mourning,'' said crew leader and Bethesda resident Paul Meter, 22, shoveling wood chips into a wheelbarrow.

Barbara Orejuela, 20, said ''It's kinda rough working here now, because I'm the only female,'' but said she is ''not the type to sit behind a desk and worry about my fingernails.''

As part of the program, corps members are required to spend five to 10 hours of their 40-hour work week in outside courses. One foreign-born member takes English language classes. Several members are completing their high school diploma equivalency requirements, while others will take courses at Montgomery College, Shepard said.

During bad weather, the workers attend film and lectures on environmental preservation or do inside carpentry and electrical work, she said.