WASHINGTON - The first family would get a recreation room and many of the annual 1.2 million White House visitors could get out of the rain if Congress supports a 20-year renovation plan proposed Wednesday.

The estimated $300 million cost of the National Park Service proposal would be borne mostly by congressional appropriations but also partly by private contributions. The park service says it's the first comprehensive plan for the White House and its grounds since George Washington designated the area in 1791.

Six years in the making, the plan dodges the hardest question: what to do about the two blocks of Pennsylvania Avenue in front of the White House that the Secret Service closed to cars after the bombing of the federal building in Oklahoma City. Many residents of Washington say those closings have made traffic worse.

The park service has designed a pedestrian mall to replace the broad street, but says it needs Congress' approval to make it part of the plan.

White House spokesman Joe Lockhart said he did not know if President Clinton was aware of the proposal's details, but said Clinton has been involved in examining some options. ''The president and the first lady have strong feelings about how the building is accessible to the general public,'' Lockhart said.

The park service also proposes moving parked cars in the area near the White House into a proposed underground garage. The proposed recreation room, also underground, would be east of the main portico and could include a gym and entertainment area.

A pamphlet illustrating the plan noted the White House is a very formal place that has not had this type of recreational space reserved for the president's family.

A public comment period on the plan will end March 11.

The existing visitors' center in the nearby Commerce Department building would be enlarged. A moving underground sidewalk would take tours to the East Entrance of the White House.

But Ann Smith of the White House staff, who works with the park service, warned there would still be long lines outside the fence when visitors come in, especially large numbers for occasions such as the annual Easter egg roll.

For the White House staff, the plan proposes an 850-car garage under the Ellipse behind the White House, and another 290 spaces under Pennsylvania Avenue. Food and souvenir vans parked along 15th and 17th streets - the east and west edges of the area - would be moved.

''Although this will cost the District of Columbia and the vendors money,'' said the park service, ''it will reduce the visual clutter and enhance the experience of the President's Park.''

In addition to the parking, the staff would get new meeting rooms and storage space.

News media would continue to occupy the crowded ground floor of the west colonnade, where the biggest offices - some used by three or four people at once - are only about 6 feet square.

But new space would be built under the adjacent West Wing drive, and for the first time there would be special room for reporters from outside Washington, and for foreign journalists.

Lockhart said none of the changes would restrict reporters' access to the West Wing where White House staff work. By The Associated Press