Rep. Steven Gunderson, a first-term Republican from Wisconsin, was looking for reassuring signs of economic recovery on main street of small-town America the other day. He didn't find many.

At Rudie's Pharmacy in Westby, an old Norwegian farming community of 1,600, a middle-aged woman told him: "People are getting edgy, farmers are having problems."

At Dregne Hardware a few doors away, the word from David Dregne was the same. "This has been a down year for us, no doubt about it," he said. "People aren't spending money. High interest rates are killing us."

And recent declines in interest rates have not been reassuring. "We tend to be skeptical here," Adrian Hendrickson, an officer of the Westby-Coon Valley State Bank, said. "We think this is a political thing by Republicans and Democrats to save their necks. That's the perception here."

Gunderson's political neck is in a precarious position. He beat a three-term Democrat in the Reagan landslide two years ago, and has been a steadfast supporter of President Reagan's economic program ever since, so much so that the Democratic congressional campaign committee has labeled him a "Reagan robot."

Now he is running in a year when the Republicans will have a weak statewide ticket. His Democratic opponent, state Sen. Paul Offner, "has based his entire campaign on the economy and Ronald Reagan," Gunderson said. "It's obvious that he's running more against Reagan than me."

The economy is stagnant in Gunderson's 3rd Congressional District, an area of gentle rolling hills and small towns in western and southwestern Wisconsin. Unemployment, at 12 percent, is above the national average. Farm prices are down, and dairy farmers have been told that Reagan-supported cuts in the dairy price-support program will cost the typical producer from $2,500 to $4,000 next year.

This would be heavy baggage for any Republican to carry. The district, one of the nation's premier dairy areas, contains as many dairy cows as people.

But Gunderson, at 31 one of the youngest members of Congress, is a savvy politician who was elected to the state legislature when he was 24 years old, fresh out of radio broadcast school.

As early as last January, he staked out a reelection strategy that called for him to localize his campaign as much as possible to separate himself from the economy.

For most of the year, this has meant an all-out attempt by the young congressman to establish some independence from the Reagan administration. He has picked his issues carefully, tailoring them to the district.

He opposed the administration on dairy price supports, cuts in student grants and loans (the district has five state-supported universities and about 45,000 college-age students) and on increased defense spending. He has also tried to become "a national spokesman" for recreational interests on the Mississippi River, which flows along the western boundary of the district.

For the Labor Day recess, his strategy meant Gunderson avoided debates with his Democratic opponent and concentrated on personalizing his campaign.

The district has only two cities, Eau Claire, population 45,000, and La Crosse, population 51,000. So Gunderson spent his days tirelessly hopping from one small town to another, "mainstreeting," as he called it, and spent his nights meeting with dairy farmers.

Campaigning from 7:30 a.m. to 11:30 p.m., he visited 21 towns this week alone. Reagan's name seldom came up during these visits.

Whenever a specific complaint about the administration surfaced, Gunderson backpedaled.

When farmers at one meeting asked why Gunderson hadn't brought Agriculture Secretary John R. Block to the district, he replied, "I haven't figured out a way we could get enough security to get him in and out of here alive."