Only 22 days were left on Marine Cpl. Thomas Butt's year-long tour of duty in Vietnam when he set out on what was to be his final, fateful patrol into the dense jungle of Quang Tri province in March 1967.

His outfit, Company One, 3rd Battalion of the 3rd Marine Division, had seen combat five or six times during his tour, but "all I was looking forward to was going home," the Rockville resident recalled in a recent interview. "After this one, that was it for me."

Nineteen years later, Butt's 17-year-old son, Michael, has embarked on an odyssey through the halls of government to find out why his father never received a medal for heroic actions that day.

Thomas Butt, 39, has not sought the medal for himself. "In fact," he said, "I've tried to block a lot of this stuff out. We were trained to stick together and we did what we had to do to help each other. We really didn't look at it as a hero kind of thing."

At dusk that day in Quang Tri, as Butt's unit was setting up night ambush positions on a small hill, it was attacked by a wave of North Vietnamese Army soldiers. His 35-man unit was surrounded by an estimated 250 NVA regulars, according to an official account of the battle.

In the 90-minute firefight that followed, Butt's commanding officer, Lt. John P. Bobo, lost a leg when a mortar round exploded. Refusing to evacuate, Bobo tied off his leg stump with a belt and continued fighting until he was mortally wounded. Butt, who was at Bobo's side, also was wounded.

"When I first got shot in the arm, they wanted to Medivac me out and I refused. I traded my rifle with Lt. Bobo, who had a .45 -caliber pistol , and I used it with my left hand," he recalled.

As Butt dragged one comrade out of the line of fire, he was shot for the third time in the leg, but continued fighting until the battle subsided.

Bobo was posthumously awarded the Congessional Medal of Honor. Butt spent the next 13 months recuperating in Bethesda Naval Hospital, not far from where he grew up in Rockville.

He said he vaguely remembers an officer telling him at his hospital bedside that he, too, had been cited for valor. But no medal was ever awarded.

"I never really gave it much thought after that," he said.

Ray Rogers, a first sergeant who was the only ranking officer to survive the attack, remembers Butt taking ammunition to the front, giving him a bandage for his wound and assisting him to safe ground from an exposed position where he had been shot.

Rogers, who received the Navy Cross for his actions, assumed command after other ranking officers had been killed, led wounded troops to safety and directed counter-attacking helicopter gunships by radio, according to his commendation.

Joseph S. Lempa of Tulsa, who was on the hill, said he saw Butt pull Rogers to safety and provide covering fire for Bobo. He also said Butt directed the fire of his machine gun crew during the battle.

Added D.J. Gomez, another veteran of the battle: "When we came up there everyone was telling me Tommie saved the first sergeant's life and saved the life of his own machine gun team."

Seeking a medal for his father "is something I had to do for him," said Michael Butt, who lives in Union Bridge, Md. He called it "an attempt to make one Vietnam veteran feel good.

"The fact that that veteran happens to be my father just makes it a little more special," he said.

Thomas Butt, a graduate of Richard Montgomery High School, joined the marines in 1965, knowing he probably would be sent to Vietnam.

During his 13-month tour, he participated in search-and-destroy missions, reconnaissance patrols and in Prairie II and Prairie III, two major operations for which his division won a Presidential Unit Citation.

Butt, who is divorced from Michael's mother, now works for Bechtel Corp. in Gaithersburg as a designer of nuclear power plants. He still has twisted scars on his right arm from the war.

He received the Purple Heart for his wounds and a Vietnam Service Medal, but there was no record of his deeds in Quang Tri province at Marine Corps headquarters, his son said.

Michael Butt, an honors student at Walkersville High School in Frederick County, said he knew he would probably have to struggle through yards of red tape to secure the medal. So he began his project by talking to a local Marine recruiter.

He learned he would have to piece together war records and collect statements from men who were there to verify his father's heroism and submit those documents to the Marine Corps.

In the last six months, Butt has been able to contact four of the Marines who fought that day at his father's side, including a man his father pulled from the line of fire.

It has been like unraveling a mystery, he said.

He found one of his father's ex-Marine buddies through an advertisement in a veteran's newspaper.

The Veterans Administration put him in touch with another man by checking its hospital records. He said he found a third by calling everyone in a Chicago telephone book with the same last name. He finally reached the uncle of the man he was looking for, he said.

Using the federal Freedom of Information Act, Butt also obtained previously classified Marine documents detailing the activities of the 3rd Marine Division in Vietnam, which contained an account of the battle.

To receive a belated medal, a commanding officer or others who witnessed the action must submit a statement to the Decorations and Medals Branch of the Marine Corps. A spokeswoman said that office receives two or three inquiries a year. The statements are reviewed by an awards board and a final determination is made by the secretary of the Navy, she said.

Michael Butt said the ex-Marines have all agreed to write on his father's behalf.

"This is something I have to do for him," the teen-ager said. "I love my father and I owe my father as any son owes his father, and I want to do this as a special kind of gift."

Said Gomez, the former Marine buddy: "Even if Tommie doesn't get a medal, one of the good things that has come out of this is that all of us guys who haven't talked to each other in 20 years are now planning a reunion in August."