ROMA, Texas—A cold wind whipped down the Texas plains on the night last month that Sharon Smith, 68, and her husband, Bill, 73, arrived here to be work-campers.

In the dark, they had trouble setting up their camper. But Sharon Smith, a former teacher's aide from Sioux Falls, S.D., said she looked up at the starry sky, shook off a few of the burrs she had picked up lying on the ground working on their truck, and told herself it would get better.

It did.

The life of a work-camper, volunteering in places like Falcon State Park in deep South Texas in return for free rent, is not without its bumps. But as Smith also quickly discovered, the rewards can be deep as well—like making cinnamon rolls as part of her job at the camp recreation center, where she and her husband are working as hosts through the end of March.

“;We're here for three reasons,”; she said, as she spread sugar on the dough. “;No. 1, we like to travel. No. 2, we like people. And No. 3, we're on a budget.”;

An itinerant, footloose army of available and willing retirees in their 60s and 70s is marching through the American outback, looking to stretch retirement dollars by volunteering to work in parks, campgrounds and wildlife sanctuaries, usually in exchange for camping space.

Cash-strapped park and wildlife agencies say that retired volunteers have in turn become all the more crucial as budget cuts and new demands have made it harder to keep parks open.

Work-campers come together in one place—leading nature walks or staffing visitor centers, typically working 20 hours to 30 hours a week—then take off to their next assignments. As they move about, they keep in touch with one another through cell phone numbers, e-mail addresses and Facebook postings, creating virtual communities filled with the people they meet.

Camp life, especially in this bird-watching hotspot, revolves around the great outdoors: picking up trash, guiding visitors and, with luck, perhaps spotting the rare roadside hawk that has been reported in the Rio Grande Valley. Night brings a round of socializing: wine around the picnic tables out by the bird feeders, an open-mic sing-along at the recreation center, an evening walk through the South Texas scrubland.

Estimates of the number of work-campers nationally vary, but a spokesman for Kampgrounds of America Inc., a private company that franchises camps, said that 80,000 or so might be a good guess, based on KOA's percentage of the camping market and the number of its work-campers.

“;It attracts a certain kind of person,”; said Wendy R. Forster, 70, a retired biologist who lives alone in her motor home and has been leading bird-watchers' walks here since January. “;There's a lot of companionship and security.”;

Recession has cut a fierce crosswind through the subculture, recreation experts and campers say. Some parks in California that once needed volunteers have closed, for example, as the state's budget crisis has intensified. Many campers are also trying to stay longer in one place to cut travel expenses.

But other recreation managers say they have become more dependent than ever on a national network of volunteers, partly because of spending cuts and partly because remaining staff members have to prioritize what they can do.

“;Basic trail maintenance, for example—picking up trash,”; said Nancy C. Brown, who coordinates volunteers for the South Texas Refuge Complex, which includes three large wildlife areas. “;It's important for wildlife purposes, but when you're faced with a choice of dealing with oil and gas permits or maintaining a trail, the trail is the first thing to go.”;

In the last decade, Brown said, the number of campsites set aside for volunteers in the complex, including those at Falcon State Park, has risen twentyfold, to 65 from three.

In some places, the retired volunteers are about the only staff members left.

“;We did a state park in Arizona this year that had laid off so many people, we basically ran it,”; said Carolyn Miller, 71, a former small-business owner from Colorado who has work-camped from Alaska to Maine with her husband, Warren, 73. For many work-campers, the appeal of a nontraditional retirement was also linked to a life-changing event—the death of a spouse, a divorce, money trouble, a midlife reassessment of priorities. For whatever reasons, they said, staying put became an unappealing or unavailable option.

And for some, there is romance to be found. Sandra Noll, 65, a retired nurse who has been leading canoe trips for bird-watchers on the Rio Grande since early January, met her partner, Erv Nichols, 66, three years ago.

Nichols, a retired photographer from Big Bear Lake, Calif., had set out to downsize his life. With Social Security as his only income, and two previous marriages that ended in divorce, he was so sure of a solo life, he said, that he ripped out the front passenger seat of the little motor home that a friend had given him as a gift.

Noll, who was reassessing her own life after a divorce and a move back West, where she grew up, found Nichols' zeal in tossing aside his possessions appealing. “;You wanted to simplify your life,”; she said, glancing across the table at him in their little trailer. “;That drew you to me.”; Forster, the retired biologist, became a volunteer partly out of grief. When her husband died of cancer 17 years ago, in his 50s, she immediately set off, she said, continuing the motor-home life they had imagined together, but now on her own. She has led bird-watching trips all over the country and has already made plans to come back here next year.

“;We're nomadic,”; she said. “;But a lot of us are coming back next year, so that will be a reunion.”; Other campers are moving down the road. Noll and Nichols, for example, are headed next to Nebraska, to work as guides along the sandhill cranes' migration route. Starting in June, the Smiths, from Sioux Falls, will work on an island in Puget Sound. Ellen Lawson, 66, of Evansville, Wyo., will head for a dulcimer festival in Mississippi. She said she was already dreading the goodbyes when she and her husband, Ron, 67, leave here in March.

“;I cried when I left home to come here,”; Lawson said while raking leaves at Falcon State Park's Butterfly Garden, “;and I'll cry when I leave.”;