SAN FRANCISCO — “This is one of my favorite things to do,” Barry McGee said as he drove along the Bayshore Freeway on a glowering winter day, pointing out random patches of new graffiti. He was supposed to be talking about his traveling midcareer retrospective, which opens Saturday at the Institute of Contemporary Art in Boston. Instead, he was revisiting some of the places where he’d spent time in the late 1980s and early ’90s, as he rose to prominence as the graffiti artist known as Twist.

“That was the key, to have every rooftop in San Francisco,” Mr. McGee reminisced as he took an off-ramp down toward the industrial reaches of the Mission District, one of many places where he and his crew once tagged the road, safety barriers and every visible roof below. “It seems completely ridiculous now,” he said, laughing, “but then it was the most important thing.”

Since those days, the whole South of Market area, once known for its seediness, has been redeveloped, gentrified. Mr. McGee had to drive past several blocks of trendy loft buildings before finding a slice of ruined waterfront that resembled the streets he once roamed. He finally stopped at a crumbling warehouse by the bay.

As he searched for an entrance, Mr. McGee recalled that he and his friends had once plastered that building and others many times over with writing and drawings. “It’s the last square mile of San Francisco that’s like this,” he said. “You feel it closing in, though.”