BIG TWENTY TOWNSHIP – The Canadian border quickly blends into the vast stretch of wilderness across northern Maine.

The only way you’d know you were on the border, short of a global positioning system, would be if you stumbled across a marker on the ground. Otherwise, you probably wouldn’t realize you’d just crossed into another country.

“You can walk across the border, and nobody’s going to know,” said Kevin Haskew, who leads a team maintaining the bulk of Maine’s 611-mile stretch of border for the International Boundary Commission.

Altogether, the United States has three underfunded and understaffed teams devoted to maintaining the 5,525-mile border.

That could change now that terrorist attacks have focused attention on what’s described as the world’s longest undefended border.

“Things might be changing with the events of the past few weeks,” Haskew said. “We might even be getting a bigger budget.”

The International Boundary Commission, which was created by a treaty in 1925, has the job of surveying the border and maintaining more than 8,000 monuments and reference points dotting the ground like steppingstones.

Its workers also are responsible for slashing a 10-foot “vista” in the woods on both sides of the border. From above, it looks something like a utility easement with occasional markers down the center.

The United States devotes less than $1 million a year to the task and much of the equipment, including some military surplus items, is outdated. Canadian counterparts work with a similar budget.

“We need to replace a lot of equipment that’s just worn out. We have very few pieces of equipment that aren’t worn out,” said Kyle Hipsley, the agency’s acting U.S. commissioner in Washington, D.C.

The 1,952-mile Mexican border is handled by a much larger agency, the International Boundary and Water Commission, which has a U.S. budget of $30 million. Its duties include flood control, sanitation issues and sharing of waters from the Rio Grande and Colorado rivers, in addition to marking the border.

On the northern border, crews are supposed to clear the brush every 15 years. In reality, the goal is not always attained, Hipsley said, and the border has become difficult to distinguish in some areas.

In Big Twenty Township, at the northernmost point in Maine, the rugged border terrain has become overgrown with alders, maples and young spruce. The last time crews cleared it was in 1986.

“It’s wide open, and it’s overgrown,” said Haskew, who stepped off his all-terrain vehicle to survey a nameless, rain-swept ridge capped with a 4-foot-tall stainless-steel obelisk marking the border.

One thing the commission is not responsible for is monitoring the border for illegal aliens, smugglers or terrorists. That’s the responsibility of the U.S. Border Patrol and Immigration and Naturalization Service.

While the Immigration and Naturalization Service deals with checkpoints, Border Patrol agents are responsible for catching those who try to slip by. The agents use ATVs, and sometimes snowmobiles in the winter, to patrol the most remote areas of the border.

U.S. and Canadian officials have pledged to tighten security on the border. Maine Gov. Angus King has even suggested using National Guard troops, already on duty in Maine airports, to assist agents along the border.

There are 334 Border Patrol agents on the entire Canadian border, compared with 9,056 agents on the Mexican border, said Callie Gagnon, spokeswoman for the Immigration and Naturalization Service in Vermont.

None of the suspects in the Sept. 11 terrorist attacks is known to have crossed the border from Canada.

But one person who is in custody as part of the terrorism investigation entered the country through Canada a few weeks before the attacks. The Pakistani has been detained since Aug. 30 when he tried to cross the border at Massena, N.Y.

People slipping across the border was on the minds of Haskew’s crew as it wrapped up its work, which runs from May to September.

At Estcourt Station, one of 32 staffed border crossings in Maine, the border is overgrown. Someone could cross the border within 50 yards of the customs checkpoint without being seen.

There are another 20 or 30 roads and paths crossing the border, many of them used by logging companies, between Estcourt Station and the next checkpoint 75 miles away at St. Pamphile.

“How easy is it to get across the border? You look at the logging roads. How are we going to stop them?” said Haskew. With a shrug, he added, “It’s just my job to cut the trees and repair the monuments.”

This summer, Haskew’s crew kept busy surveying the border along the St. Francis River. Likewise, a Canadian team was surveying the border along the southwest branch of the St. John River.

Both rivers were used to designate the U.S.-Canadian border, but both have changed course over the years. In some places, the St. Francis River has veered 400 feet from its original route. At some point, 200 markers will be needed to mark the boundary, Haskew said.

Other projects included a contract to clear brush in Coburn Gore and in the Pasayten Wilderness in Washington state; surveying along the Detroit River in Michigan and Lake of the Woods in Minnesota; and rebuilding monuments in Vermont.

Part of the reason the teams are stretched so thin is that the entire border has to be resurveyed to update the coordinates in keeping with new standards brought about by global positioning technology, Hipsley said.

For the most part, the border is in good shape, he said.

He said an additional $100,000 a year is all it would take to replace aging equipment and fully staff his crews. That may not seem like much but it would be a jump of roughly 10 percent from his 2002 budget of $979,000.

“We’re not trying to build an empire,” said Hipsley, a former field surveyor. “We’re just trying to do our job.”