The words printed on the buses that drive through Kawaguchiko, a scenic town in the foothills of Japan’s tallest and most sacred mountain, were as reassuring as they were disconcerting: “Preserve the Nature of Mt. Fuji.”

The message was a reminder that despite years of effort, the millions who visit the mountain and nearby towns each year and the plethora of businesses that serve them continue to have a profound impact on the environment, whether through mounting trash, poor air quality or suburban sprawl. Mount Fuji, or Fujisan as it’s known to the Japanese, is the nation’s most recognizable natural landmark, a conical volcano immortalized by artists like Katsushika Hokusai and Utagawa Hiroshige. These days, the mountain, less than two hours from Tokyo, is a playground for rich and poor. Climbing the mountain is on many hikers’ bucket lists.

But easy access to the mountain — drivers can park about halfway to the peak — has been a mixed blessing. Last year, nearly 320,000 people made the climb, yet 25 died trying. Illegally dumped garbage fills the forests. Traffic chokes surrounding roads and paths to the peak. Big events like the jazz festival at Kawaguchiko draw thousands of fans.

Countermeasures have been taken. Low-waste toilets have been installed on the mountain, and tens of thousands of volunteers haul away tons of trash every year. Hybrid buses shuttle visitors to trailheads. This summer, climbers were asked to contribute a fee to help preserve the environment. But the measures will do only so much because the parade of visitors is likely to continue, especially now that Mount Fuji has been added to Unesco’s World Heritage list as a cultural asset (the 13th in Japan) for inspiring artists, poets and religious pilgrims.

Hearts swelled in Japan after the June 22 designation was announced. The question is whether it will draw so many more visitors that the qualities that made Mount Fuji a cultural asset in the first place will be diminished.

Mount Fuji is bracing for a big jump. Other heritage sites in Japan including Hiraizumi in Iwate Prefecture, Shirakawa-go in Gifu Prefecture and Yakushima Island in southern Japan all saw an increase in visitors after they joined the list in recent years.

Seiichi Kondo, Japan’s Commissioner of the Agency for Cultural Affairs and a former ambassador to Unesco, said that more visitors are expected to visit Fuji, but that regulations may be strengthened to offset any degradation. “After all, the main objective of the inscription of particular sites on the list is to mobilize international efforts to protect them from various dangers, such as military conflicts, development and tourism,” he wrote in an e-mail.

Mr. Kondo said the number of tourists has risen 15 percent so far this year — indicative of the Japanese view that the mountain is “a special symbol of nature and their identity.” According to other estimates, the number of visitors could double in the coming years. In the first 10 days of July alone, the number of hikers who passed the Yoshida Gate — a popular path to the peak — jumped 50 percent over the same period last year. Hikers were asked to bring portable toilet kits because the influx of visitors is overwhelming available infrastructure.

Officials had tried on and off for 20 years to have Mount Fuji named a World Heritage site, and its inscription was front page news in June, when my wife and I visited Japan. Eager to see the celebration, we rode two hours by train to Kawaguchiko, a town 10 miles from the mountain.

When we arrived at the small station, we knew instantly that many others had the same idea. After we boarded the Retro Bus that circles the town, our driver warned us that traffic would delay our trip. We crawled past gas stations, car dealers, fast-food joints and shops like Fujiyama Cookie.

We got off at the Natural Living Center, where a guard was directing buses in and out of the parking lot. Nearby, vendors sold vegetables, fruit and crafts. The lakeshore gardens were pleasant though Mount Fuji’s peak was obscured by thick clouds. As we walked among hundreds of photo-snapping tourists, our search for a view had little of the poetic resonance that Japan’s Unesco bid suggested. So we rode the bus to the Kachi Kachi Yama Ropeway and took a cable car more than 3,000 feet to the top of the mountain. There, the whistling wind mixed with the sound of revving motorcycles below. But at least we could imagine what the mountain looked like.

Politicians, environmentalists, local police and residents have worked for years to find a formula that preserves access to the mountain without undermining tourism. Solutions have been hard to find because there are so many stakeholders. Mount Fuji is in a national park, straddles two prefectures and is surrounded by five lakes and many towns, including Kawaguchiko. Volunteer groups have led the effort to remove the trash dumped near Mount Fuji. According to the Fujisan Club, a nonprofit group, volunteers hauled away 77 tons of garbage in the fiscal year that ended March 2013.

“There is no way to stop people from coming to the Fuji Five Lakes area, so it’s a difficult problem,” said Shomei Yokouchi, the governor of Yamanashi Prefecture.

Heita Kawakatsu, the governor of Shizuoka Prefecture, which also borders the mountain, said there are plenty of inns and restaurants to accommodate a rise in visitors. He is more concerned about a surge in the number of hikers, and favored shutting the mountain during the winter for safety reasons. “We must observe the capacity for climbers and the balance between recreation and the object of art,” the governor said.

Mr. Yokouchi of Yamanashi Prefecture opposed the winter ban because serious climbers still need to train in the winter and because the cottages on the mountain would suffer.

For better or worse, Mount Fuji is so popular and easy to reach that it is nearly impossible to cordon off. The climb is not technical, but it is deceptively arduous. The trails are rocky and often crowded, the weather can change rapidly and even for climbers in good shape, 12,400 feet is a long way to go. Each year people are hurt or die from hypothermia, heart attacks and falls.

To help pay for preservation efforts, climbers during a 10-day stretch this summer were asked to donate 1,000 yen ($10.75). If the fee is made permanent, millions of dollars could potentially be raised.

Keisuke Tanaka, head of the Whole Earth Nature School, which runs eco tours of the mountain, said that the donations should be used to improve trails and toilets and add waste treatment facilities and multilingual signs. The government, he said, should control the number of visitors.

To that end, new guidelines for climbers who scale Mount Fuji out of season were introduced in July. Hikers will have to submit their plans in writing and carry the proper equipment. With more visitors expected, the world will be watching to see if these and other measures work.

“More people than ever will come,” said Shigeru Horiuchi, the mayor of Fujiyoshida City. “How we protect the natural environment and how we limit tourists and climbers are the biggest challenges.”