Mike Humphries stood ensconced in a three-foot deep hole in the ground and pecked at the chocolate-colored earth with a metal scraper. At first only clumps of dirt fell from the tip of the scraper, then a tiny triangular piece of earthenware dropped into Humphries' hand. He held it up to the sunlight and examined it.

"There you go - a piece of Indian pottery," he told a bystander. "Probably the late Woodland period. Like about 900 B.C."

Humphries, archeologist for St. Mary's County (Maryland's first county), was standing on a plot of land just south of Leonardtown considered to be one of the most important archeological sites in Maryland.

Initial excavations have already turned up prehistoric pottery and crude arrowheads dating from as far back as 5,000 B,C, This summer, an archeological park - the first of its kind in the state - will be set up at the St. Mary's site to permit the public to take part in the actual excavations.

"From what we'rent that the people who settled in St. Mary's County, throughout the ages have lived on this same spot," Humphries said as he scanned the six-acre site atop a hill overlooking Breton Bay and the Potomac River.

To the west, the Northern Neck of Virginia juts into the Potomac like a thick green finger pointing to the tree-lined St. Mary's shore. From that very spot, now studded with dried-out corn stalks, Indian settlers in Maryland some 5,000 years ago ate their seafood meals and battered out the stone arrowheads they used to kill animals and tribal enemies who might creep up from the shore.

According to Tyler Bastian, state archeologist, projectile points found at the site (currently called Abell's Wharf), have led archeologists to believe that the site was inhabited by Indians as early as 7,000 years ago.

The Maryland Archeological Society, in cooperation with Bastian's office did some digging at Abell's Wharf over the past two summers and uncovered projectile points from the Late Archiac period (5,000 to 2,000 B.C.) and some early Woodland pottery (2,000 to 1,000 B.C.).

The archeologists also found a trash pit where prehistoric Indians disposed of oyster shells and animal bones. Humphries has found several Indian clay beads, bits of clay pottery, and stone knives and choppers near the trash pit.

In another trash pit on the site dating from colonial times, Humphries found pieces of ceramic pottery along with a 1973 silver coin and some bone-handled knives.

Humphries said county land records show that a tavern stood on the site in the 18th century and archeologists last summer were able to trace the outline of the structure in the soil. Nothing of the original tavern or its foundations remains.

Humphries, a local school teacher whose avocation is archeology, was appointed county archeologist in 1971 when the county commission also designated a county historian. Humphries said he knew of the Abell's Wharf site two years ago, but no test escavations were done until the area was about to become a gravel mining state.

When Abell Clarke, the gravel miner who owned the land at the time, heard about its archeological importance, he donated the six acres to the county.

Last week, George Washington University completed a contract with the county to send archeology instructors and students from its summer field school to excavate the site.

The plan is for St. Mary's residents and visitors to spend a weekend at the site, get some training in the basics of archeological digging, then help the George Washington team with the excavations.

The weekend will aslo include an outdoor slide show on the county and tours of St. Mary's City - the first settlement in Maryland - and of Point Lookout, the site of a Union Army prisoner of war camp, Humphries said.

According to Bastian, there are other archeological sites as old and as significant as Abell's Wharf, such as an area at the mouth of the Monocacy River in Frederick County. Because of budget constraints, the state has no plans to excavate these sites, he said.

Former County Commissioner Jay S. Guy, who is active in the Abell's Wharf project, said the county is trying to use its rich archeological history to attract tourists. The County Commission, he said, began concentrating on tourism, after county residents voted their support of a law prohibiting heavy industry from coming to St. Mary's.

As in colonial times, most of the county's residents remain farmers and watermen. The tourist trade has been limited mostly to people who come for sport fishing.

According to current Commissioner Ford Dean, the county has earmarked thousands of dollars for historical projects like Abell's Wharf, which has been allocated $20,000.

The county contributed $25,000 last year for the production of Wings of The Morning, a drama depicting the settlement of St. Mary's City, the county seat.

And, in 1975, the county opened the Potomac River Museum at Colton Point to show the importance of the river in the county's history.

Altogether this current fiscal year, the county has spent about $104,100 for tourist - related and historicak projects - or about 1.6 per cent of its $16 million budget - according to finance director Joseph P. O'Dell.

Meanwhile, the St. Mary's City Commission, with state and federal funding, is digging up the foundations of 17th and 18th century buidlings in St. Mary's City."We feel tourism has not been given a fair chance in St. Mary's County. We're just as important as Williamsburg," Guy said.