RUPERT, Vt. - One sure cure for the mud-season mopes is visiting an authentic New England sugarhouse, where steam billowing from the roof vents signals that the alchemy of spring has begun. The annual sugaring celebration here at Merck Forest & Farmland Center holds rich rewards for urban pilgrims, especially families with kids.

First, head for the pancake feast, served with maple syrup and an optional side of sausages made from the farm's own pigs. Afterward, meander over to the evaporator, the contraption that boils down watery maple sap. Bigger than a UPS truck, this monster unit is one of the biggest anywhere, says Ken Smith, the center's director. "It can handle as many as 1,200 gallons of sap a day." As many Vermont schoolchildren know, that yields about 24 gallons of rich, golden syrup. Workers also will be demonstrating how to make traditional maple-sugar candy and the frosting-like confection called maple cream.

Step onto the porch to take in a panorama of the hills rippling through the 3,100-acre property owned by Vermont's oldest nonprofit conservation organization, which manages the land to demonstrate sustainable farming and forestry. (George W. Merck, chief of the pharmaceutical company, had a farm here and founded the center; it was renamed in his honor after his death in 1957.) Then stroll a couple of hundred yards up to the barn to greet newborn lambs and check out enormous pigs, chickens, and a rare breed of shaggy cattle.

Word to the wise: Bring footwear to handle mud, ice, snow, or all three.

Maple Open Sugarhouse Weekend, March 29-30, Merck Forest & Farmland Center, Route 315, Rupert Mountain Road, Rupert, Vt., 802-394-7836, merckforest.org. Both days 10 a.m.-3 p.m., breakfast served until 2. Free, except breakfast; adults $5, children $3. Directions: Rupert is about 210 miles, or nearly 4 hours, from Boston. Take Route 2 west to Interstate 91 north to Vermont. Take exit 2 in Brattleboro and follow signs for Route 30. Follow Route 30 for about 50 miles through Manchester Center to Route 315. Turn left onto 315 and follow for about 2 1/2 miles to top of hill. Driveway to the center is on the left; up the driveway are the parking area and visitors center.