In 1944, when Carl Jones was 47 years old, he led a group from the Wanderbirds Hiking Club along a little-known route into Rock Creek Park called the Melvin Hazen Trail.

The trail started at Reno Road and Rodman Street NW and wound east through deep woods to Connecticut Avenue. After crossing the avenue,it dipped back in the woods, ran along hillsides and back and forth across a creek until it emerged in the park near Pierce Mill.

It was a nice route, and well maintained, Jones kept it in the back of his mind and returned to it three or four years later, but it had fallen into mild disrepair. "I went back every few years after that," Jones said last weekend, "and each time I did it was in worse condition."

Last winter, Jones, by then an octoganerian, read a story in the Post's Sports II section that detailed a Potomac Applachian Trail Club commitment to restoring hiking trails in Rock Creek Park. He decided he'd do his share by bringing the Hazen Trail back to life.

"It's very convenient for me," he said, "because I can use it to walk from my home on Wisconsin Avenue down to the park." At 81, Jones tries to walk at least four miles every day "just to keep in shape."

So he began drifting down to the Hazen Trail whenever the weather would permit it, armed with a sharp kitchen knife. In the course of 15 or 20 visits, he managed to mark out the abandoned 1 1/2-mile route with rag strips, cut back some of the undergrowth and beat a recognizable path along the length of the trail.

PATC members were busy doing similar work on other side trails and the seven-mile main trail that eventually will run from the northernmost D.C. section of the Park down to the Potomac. They knew about Jones's project and approved it, then left him to his own devices.

"He did most of it on his own," said Tom Floyd, director of trails for the PATC. "He moved an awful lot of stuff just with his hands."

Then last Saturday, a 16-person work crew from PATC and FORCE (frineds of Rock Creek Environment) gathered to put some finishing touches on the steeper sections of the Hazen Trail.

They met at 8:30 a.m. in 20-degree cold at a parking lot just north of the mill. Among the first people there was Jones, dressed in wool pants, a bright Scottish beret and a backpack loaded with his lunch.

"I see you know a little bit about the woods," he nodded to a newcomer. "You seem to know how to dress properly."

There were kind words indeed, from a veteran woodsman like Jones. He is the eighth person on record to have walked the entire 2,000 miles of the Applachian Trial. He started near where he grew up in the coldest reaches of Northern Vermont, then moved south, as his family did to Massachusetts. He did the Mid-Atlantic sections after he moved to Washington in 1941 to take a job as an economist with the Commerce Department.

The days of long hikes are pretty much behind Jones now. "At 81, I no longer can do the things that I could do when I was only half as old," he said.

But age hasn't stopped him. He wielded a hoe with gusto Saturday while men and women a quarter his age and younger battled the frozen earth with pickaxes, shovels and other tools, trying to level the Hazen Trail and build walls to stop erosion.

It waa hard work, and after a half a day. Jones thought he'd had enough. He headed back toward Wisconsin Avenue and home.

Floyd and a couple of others offered to see him on his way. They strolled with the old man through the crisp snow, listening to the gentle burbling of the brook.

At Reno Road, the last few steps out of the woods were steep and icy Someone offered Jones ahand. "That's all right," he said, waving the offer aside. "I'm not completely debilitated, you know."

When Jones first discovered the Hazen Trail on a topographical map decades ago, he thought it was two trails. "It's in two sections, you see one above Connecticut Avenue and one below. I thought the westernmost trail was the Melvin Trail and the other was Hazen Trail," he chuckled.

With all due respect to Melvin Hazen, commissioner of the District of Columbia in the 1930s, it's time to rename half of it the Carl Jones Trail.