The Twin Cities CIA office was a mystery 40 years ago. It had a local phone number but listed no address, and when you called, they wouldn’t tell you where they were located or why they were here.

In 1977, the Minneapolis Star assigned reporters Pat Marx and me to see what we could find out. It was a bumpy ride.

We got a special phone line with no ID installed at the Star and ran a classified ad asking anyone with information about the CIA to call.

The phone rang the first morning the ad ran. I picked it up. “Who are you?” the voice said. Flustered, I replied, “Randy Furst at the Minneapolis Star. Who are you?”

“The CIA,” the voice said. He wouldn’t say where they were located.

We tried another angle. We’d come across the name of a CIA officer, Robert Wallace, who was based here and running for the board of the Citizens League, a local advisory group. Pat Marx and I staked out his home in south Minneapolis with a plan to tail him when he went to work.

Wallace pulled out of his driveway. We followed him as he drove onto Interstate 35W. We didn’t know what we were doing and within seconds, we had lost him.

However, he was heading south, and we guessed he might be going to the Fort Snelling Federal Building, so we headed there. We went inside and down to the basement mailroom.

“Where’s the CIA office?” I asked a man sorting mail.

“Oh, they are up on the second floor,” the man said.

We wandered around the second floor until we saw a door with no sign and opened it. Inside was a window with no sign, either. A clerk was behind it. “We’d like to speak to Bob Wallace,” I said.

The clerk stepped away from her desk, then returned and said Wallace was not there. We were clearly in the right place. The clerk asked who we were. We told her and a few minutes later, Paul Hendrickson, the CIA regional director, came out in the hallway and talked to us. He told us the CIA’s location had not been made public because it might lead to demonstrations outside the office and “nut visits.” He would not tell us what the local CIA did.

Local debriefings

In our reporting we learned that regional CIA offices debriefed American business leaders who made trips to the Soviet Union. “Why go abroad and spy on somebody when you can get the information from a friendly American?” William Colby, former CIA director, told us in an interview.

So we called up local CEOs, several of whom acknowledged their debriefings with the CIA.

Our last job was to get a good picture. We found the Edina address of Hendrickson and photographer Bill Seaman and I parked outside his house one morning. As he pulled out of his driveway and started down the street, I walked in front of Hendrickson’s car to slow him as Seaman snapped photos. Hendrickson had on sunglasses.

He rolled down the window. “I knew it was you,” he told me. “I saw the car, called in and ran the plates.”

Hendrickson left the Twin Cities a few months later. He died about 15 years ago.

But I recently called Wallace, who now lives in Reston, Va. He said he rose to director of technical services for the CIA before retiring in 2003. He wrote a 2008 book, “Spycraft,” about gadgets and devices developed by the CIA.

Wallace said he never realized we tried to tail him. It had been alleged in those years that the CIA was engaged in domestic surveillance, but Wallace said it was not true. “We didn’t keep tabs on anything or anyone,” he said.

What did he think of our article back then? “It was a non-story,” he said.

Twitter: @randyfurst