MONTPELIER, Vt. (AP) -- It's known in northern New England as the fifth season: mud.
But the time of year when the thawing winter landscape turns dirt roads into mucky seas and paved highways into frosty roller coasters sprinkled with potholes doesn't get featured on tourist calendars.
Every place with a snowy winter has its own version, but mud season occupies a special place in northern New England. It's the ugly mirror image to the picture-perfect foliage of September and October that draws millions to look at mountains painted red and gold.
From late March to May, many hotels offer rock-bottom mud-season rates to lure people in. In the popular Killington area, many restaurants that cater to tourists close between the end of skiing and the arrival of spring, defined not by the calendar, but by pale green buds and long days that make people want to visit again.
Despite its reputation as the season to forget, cultural chroniclers ranging from poet Robert Frost to novelist Howard Frank Mosher to political cartoonist Jeff Danziger have paid homage to the purgatory that begins in late March and can last into May.
"It's emblematic of everything that's bleak and horrible about being isolated at the end of a road that you just can't get out of," said Mosher, the Irasburg writer who has for decades written about the picturesque, exceptionally rural part of Vermont known as the Northeast Kingdom and who set a 1972 short story, "Burl," during mud season to highlight the desolation of his protagonist.
Mud season does provide recreation for the creative.
In Maine, forest rangers have to warn operators of all-terrain vehicles and four-wheel-drive trucks not to get carried away with slipping, sliding and spinning during mud season. In addition to damaging roads and private property, unauthorized "mudding" can cause uncontrolled runoff that damages fish habitat in streams and lakes.
David Lovewell is a mudding enthusiast and co-owner of Barnyard All Terrain in Livermore, Maine, created to provide a legal venue for people to go mudding, with events through the summer. These days, enthusiasts know better than to take joyrides in the woods or farm fields, he said.
"You can get in a lot of trouble now. If you get caught, you're going to get arrested. It's against the law, unless you own the property, to start turning up the woods," he said.
There are also more grave dangers -- an MTV reality show star was found dead of carbon monoxide poisoning in his SUV last week with two passengers, apparently after going "mudding" in West Virginia. The tailpipe may have been submerged in mud, allowing the gas to accumulate inside.
High-tech advances in engineering and all-wheel-drive vehicles have converted mud season from a time of true isolation decades ago to a mild annoyance today. Still, roads are closed, cars get damaged and some people park their cars far from home to avoid having to drive through mud.
When the season starts and how long it lasts varies by year and location. Yet it still sucks millions of dollars from state and local road budgets, be it for gravel to fill sinkholes or material used to fill potholes.
The verdict isn't in yet on how severe this season is going to be.
"We were anticipating it to be a really bad one," said Scott Rogers, the director of the operations division of the Vermont Transportation Agency. "We know everything is really wet underneath. A lot of it depends on what Mother Nature does to us over the next few weeks."
Mud season comes before the frost fully leaves the ground. Rather than meltwater seeping into the soil, it stays near the surface. That led Robert Frost in his 1934 poem "Two Tramps in Mud Time" to write, "The water for which we may have to look / In summertime with a witching wand, In every wheel rut's now a brook / In every print of a hoof a pond."
It's most noticeable on gravel roads, but the expansion and contractions of the frost can cause pavement to heave, which in turn cracks the pavement, leading to potholes, Rogers said.
In some ways, the solutions to mud season are emerging with modern technology.
In Brattleboro, the town has posted on its website a map, updated daily, that lists the conditions of the town's gravel roads, ranking them from good to closed, said local highway superintendent Hannah O'Connell.
"It's been very well received," she said.
Several years ago, the Vermont Transportation Agency commissioned a study by the Cold Regions Research and Engineering Laboratory in Hanover, N.H., titled, "Improved performance of unpaved roads during spring thaw." The study found different systems can keep mud at bay using combinations of fabric and permeable material.