They come from what their colleagues call "that foreign land north of the Rappanhannock River," and for Northern Virginians in the General Assembly, overcoming such sneers is often the least of their problems.

So intense can be the anti-Northern Virginia bias here that Del. Gladys Keating (D-Fairfax) says, "I don't say I'm from Northern Virginia, I say I'm from southern Fairfax."

Rural and conservative legislators, who outnumber the representatives from the Washington suburbs, tend to be "put off," says Del. Warren E. Barry (R-Fairfax), by Northern Virginia's image. They regard the region as a uniquely rich and progressive area, whose economy is subsidized by the federal government and its thousands of federal bureaucrats, Barry said.

"They think of Northern Virginia as a transient community full of nonnatives who have problems they created for themselves," Barry said. "The other legislators hear about our problems from rather vocal people who are looked upon as more liberal than the rest" of the state, he said.

That attitude, Northern Virginia legislators say, is a major reason that legislation that has broad support in the Washington suburbs often gets nowhere in Richmond.

"Everybody who comes from Northern Virginia is a flaming liberal out to destroy a conservative commonwealth -- and they see some of our bills as threatening the commonwealth," says Del. Richard L. Saslaw (D-Fairfax).

Northern Virginia has more than 1 million residents, roughly a fourth of the state's population. Its 19 delegates and eight senators represents the interests of Arlington, Alexandria, Fairfax and Loudoun and Prince William counties and account for about a fifth of the assembly's 140 members.

But the area's voting clout will shortly increase after legislative reapportionment in 1980, and that prospect is reviving some old fears and prejudices among other legislators long suspicious of Northern Virginia, an area legislators often define as anything north of the Rappahannock at Fredericksburg.

"I like Northern Virginians, but they're coming down here in droves soon and we're not going to be able to get anything." complained Del. Lewis W. Parker Jr. (D-Mecklenburg) at a recent hearing on a state spending limit proposal.

The proposed 1-cent Metro sales tax in Northern Virginia, for example, has run into a stiff opposition among House members who complain the legislation is another example of special treatment for an area whose Washington related problems are not the state's concern.

That attitude and the perception of Northern Virginia as an affluent area with plenty of money to spare is similar to the way many Maryland legislators long have regarded Montgomery County.

But the affluence of Northern Virginia and Montgomery County "is all relative," according to Del. Vincent F. Callahan Jr. (R-Fairfax), "because it costs so much to live up there and we have special needs that come with our urban, suburban locals. Our problem is trying to explain that our money doesn't go as far."

A lobbyist for Northern Virginia concerns said the area's wealth "is definitely a stumbling block" whenever Northern Virginia legislators go looking for support for their bills.

"The cost of living is so radically higher than elsewhere in the state. and the urban counties have to provide so many more services than rural counties," said the lobbyist, who asked for anonymity.

"Yet, when you're from Buchanan County in the far Southwest, it's hard to understand why we need money when we seem to have so much already," he said. "The average home costs $70,000 in Northern Virginia -- you can't fight that."

And then, there's Northern Virginia's image as alien territory to contend with the lobbyist said. "We're still looked upon as carpetbaggers," he said.

"I mean technically Northern Virginia is part of Virginia, but it's regarded as Washington, D.C., gone south. We aren't thought of as really Virginians."

The joke around the state capitol, he said, "is that anybody north of the Rappahannock is a commie-symppinko and anyone south is a Virginian."

Another lobbyist who spends a lot of time in Richmond on behalf of consumer legislation said Northern Virginia legislators also create controversy because they tackle some issues that others won't touch.

"I'm told we'd be out of here in 30 days except for all the bills introduced by Northern Virginia, and they are generally bills for change," she said.

This puts Northern Virginians "very much out front" on such controversial issues as rape law reform, coastal resources management, consumer legislation, the Metro sales tax and state funding for abortions, the lobbyist said. "And that's not the traditional approach here."

A common complaint by several Northern Virginia lawmakers is that their area has had such a higher turnover in assembly representation that it is difficult to build up the seniority that leads to committee chairmanships and leadership roles. "When I first came down here to the House in 1966, I didn't get put on any influential committees because I was considered a liberal from Northern Virginia and dangerous," recalled Sen. Clive L. DuVal II (D-Fairfax).

Now, DuVal said, he has been joined in his push for progressive legislation by legislators from other areas of the state.

Senate Majority Leader Adelard L. Brault (D-Fairfax) said the problems of being from Northern Virginia "are not as bad as when I came down here 14 years ago." He cites his election to his leadership post in the Senate four years ago as proof that a Northern Virginian is no longer regarded "as a leper."

Sen. Hunter B. Andrews (D-Hampton), whose acerbic wit has enlivened many debates, said some Northern Virginians erroneously fall into a "them-versus-the-commonwealth" posture.

Despite the worst fears of Northern Virginia legislators, "they're just as much Virginians as the rest of us," Andrews acknowledged. He said that area is "blessed" with economic affluence and standards of education higher than Virginia as a whole while being "cursed" with such uniquely urban problems as Metro financing.

"Some of them tend to think we don't understand their problems, but we do," said Andrews, who was instrumental this session in pushing legislation for Northern Virginia authorizing the merger of the International Law School in Arlington with George Mason University.

"The perception here seems to be that they get it all, but they don't get it without our votes," Andrews said, noting that Northern Virginia has formed successful alliances on some issues with the Tidewater area of the state and Southwest Virginia.

Sen. Joseph V. Gartlan Jr. (D-Fairfax) said it would be inaccurate "to say we've led and the rest of the state has followed" in sponsoring progressive legislation in the assembly. But he said individual members like retiring delegation chairman Sen. Omer L. Hirst (D-Fairfax) and Del. Mary Marshall (D-Arlington) -- who have pioneered in the field of mental health and legislation on aging respectively -- have had a major impact on Virginia.

"We're the convenient butt for some friendly jokes," Gartlan said. "But the longer you're here, the more you feel accepted, and therefore, the more you feel Northern Virginia is accepted."