LUNA, NM --A single campfire likely sparked what is now the largest blaze in Arizona history, and authorities said Wednesday they've questioned two "persons of interest" as the massive wildfire and two others threaten separate corners of New Mexico. However, investigators declined to call the two people suspects or speculate on whether they'll face charges or be found liable to pay restitution. Area residents had mixed feelings about how hard officials should go after those responsible. "It's done," said Reed Schmidlin, 61, who was evacuated from his Springerville home for two weeks. "There's not a lot you can do about it." He said prosecuting those responsible would just add to the fire's cost. In New Mexico, the tourism secretary said the state had been hoping for a modest rebound in tourism this summer. But with fires burning near three of the state's four borders, she's trying to stay optimistic and reassure people that New Mexico is open for business. The fire burning in eastern Arizona's Apache-Sitgreaves National Forest continued its cross-border threat to Luna, N.M., as it grew to 478,452 acres of forest, or nearly 750 square miles, fire command team spokesman Alan Barbian said. Of that, 4,911 acres were in New Mexico and 473,541 in Arizona, making it the largest fire in Arizona history, although nowhere near the most damaging to homes. The blaze has forced nearly 10,000 people to evacuate in several small mountain communities and two larger towns on the forest's edge. It has burned 32 homes and four rental cabins Arizona's largest fire previously was the 2002 Rodeo-Chediski fire, which burned 732 square miles and destroyed 491 buildings. About 2,700 people who live in several Arizona resort communities in the forest remained evacuated. Nutrioso residents began trickling home midmorning Wednesday, and fire officials said evacuation orders for the picturesque hamlets of Alpine and Greer might be lifted in several days. Greer lost more than 20 homes and a couple dozen outbuildings as flames moved into the valley last week. Forest supervisor Chris Knopp said a campfire in the Bear Wallow wilderness was the "most likely cause" of the eastern Arizona fire. He confirmed investigators had questioned two people, but he declined to say any more about the investigation. When forest officials were first called to the fire May 29, they spotted a fire near a campfire, Knopp said. They also saw a separate fire about three miles away, but they were unsure if it was sparked by the campfire, he said. "I just hope they identify the people responsible for this," Knopp said. Asked why no fire restrictions were in place before the blaze, Knopp pulled out a picture of Springerville on May 19, after the town had received 6 inches of snow. "It seems pretty foolish for the forest to implement fire restrictions when there was just snow on the ground," he said. "If I had it to do over again, I would probably do the same thing. If I had known a fire would start, I would do it differently." Toby Dahl was evacuated from Escudilla, N.M., near the Arizona border and spent six days in a temporary RV park over 60 miles away in Pie Town, N.M. He said fire restrictions should have been in place, despite the recent snow. Dahl, 62, said his place got only 11 inches of snow all winter, compared with nearly 80 last year. "I don't have a degree or anything but I can tell you, just don't let anybody into the forest under these circumstances," he said. He wasn't sure what should happen to those responsible for igniting the blaze. But he said, "Something has to be done to make people think." Teresa Shawver, 61, who lives on a small ranch in Quemado, N.M., said she would want the perpetrators to get "the max, whatever the law would allow," if the fire was set intentionally. "If it was an accident, something got away from them, then I have a different view on that," Shawver said. The fire was "terrible for everybody around here." she said. "But if it was just an accident, then that's what it was." Though the fire's acreage grew, firefighters were holding the line on its north, south and west sides. Just across the state line, evacuation plans remained in place for the roughly 200 residents of Luna, N.M. Crews have worked to protect the town for days, cutting brush and trees and setting small fires to burn anything that approaching flames could use as fuel. Elsewhere in New Mexico, firefighters had a good day Wednesday. Crews bolstered fire lines on the southern edge of the blaze along the New Mexico-Colorado border, allowing officials in Raton, N.M., to lift some evacuation orders. Utility crews worked to repair a fire-damaged valve along a natural gas pipeline that serves thousands of customers in the Raton area and several communities to the south. But officials weren't expecting any interruption of service, Raton Mayor Neil Segotta said. The fire, which started Sunday, has burned more than 25,300 acres and was 5 percent contained. It has blackened about half the forested acres at Sugarite Canyon State Park and shut down a 20-mile stretch of Interstate 25, from Raton to Trinidad, Colo. The park and interstate remain closed. In southern New Mexico, Carlsbad Caverns National Park has been closed by fire this week but reopened for the Wednesday evening bat flight. Park officials planned to resume normal hours Thursday. The fire burning around the park has charred more than 47 square miles. New Mexico tourism officials were keeping a close eye on the fire danger heading into the Fourth of July holiday. Tourism Secretary Monique Jacobson said much of the department's focus for building tourism has been on keeping New Mexicans in New Mexico. She says the department now is also trying to be proactive to keep travelers from being scared off by the fires. Cathy Connelly with the town of Taos said tourism there is up 9 percent and she hasn't heard of any fire-related cancellations headed into the Fourth of July. Fires have devoured hundreds of square miles in the drought-stricken Southwest and Texas since wildfire season began several weeks ago. The outlook from the National Interagency Fire Center in Boise, Idaho, calls for above-normal fire potential in those areas through September.