As she drove her motor home westward toward her native Tacoma, Dr. Dixy Lee Ray, 60, said, "Every mile I put between me and Washington, D.C., I felt happier and happier."

For nearly two years Dr. Ray was chairman of the Atomic Energy Commission and regarded as the most powerful woman in the capital. Then late last year she helped reorganize the AEC into two smaller agencies which left her without a job.

Determined to keep her, President Ford named Dr. Ray assistant secretary of state in charge of scientific affairs. But enmeshed in the State Department bureaucracy, she became so frustrated she quit in five months. "It is an agency that is tuned up never to do anything," she complains. "A decision that should take 10 minutes takes 10 days. I suppose the essence of diplomacy is to avoid taking a final position. People like me should never get involved in an agency like that."

Before Dr. Ray left Washington in June, she suggested that Henry Kissinger ran less than a tight ship at State, and she has had time to brood on the matter. "Dr. Kissinger has no interest in management," she says. "He likes to confine himself to the big picture and let somebody else worry about the pronouncements and commitments. That's where organization and administration come in. At the State Department, the staff does not have proper direction. It has to guess at what is really wanted."

When she took over AEC, Dr. Ray quickly won Congressional praise for her administrative skills and sense of political toughness. But at State, she never was one of Kissinger's coterie of advisors. Like other critics, she thinks Kissinger is unnecessarily secretive. "By nature he keeps his cards close to his chest," she says. "Nobody wants to take any responsibility because they're not sure what the Secretary wants. It's a serious situation. Our foreign policy is being conducted by one man with a very small group of advisors. He is not using the assistant secretaries appointed by the President."

The chunky (5'4", 150 lbs.) Dr. Ray has been a maverick in her style of life as well as in her public remarks. In Washington, instead of retreating to a split-level suburb, the frugal Dr. Ray purchased a $21,500 motor home and took it to a trailer park near AEC headquarters. She shared it with a poodle, Jacques, and a Scottish deerhound, Ghillie. She also scorned fashion, turning up at the office in plaid skirt, blazer and knee socks.

As Dr. Ray settled back into her 65-acre Fox Trot Farm, overlooking Puget Sound, friends reminded her that the governor's mansion, 30 miles south in Olympia, would be available next fall. Dr. Ray is ready to test the waters. She would run as a Democrat, but her party loyalties are slender. "I guess," she says, "I'm a conservative Democrat or a liberal Republican."

Dr. Ray recently signed with a lecture bureau and is also writing a book about her Washington experiences, Goodbye, America? "It's not a doomsday book," she says, "but it warns that the country could slip into oblivion if present policies continue."

Lecturing, writing, Dixy Lee Ray sounds like a politician about to take the plunge. She waves a hand toward the motor home in which she and her dogs lived. "It would make an ideal campaign vehicle. But we'll see."