LOS ANGELES — It was 4:35 a.m. on Saturday when the block-long transporter carrying a 340-ton, 21-foot-high boulder wrapped in white plastic pulled up in front of the Los Angeles County Museum of Art.

More than 1,000 people, kept on the sidewalk by a squadron of police officers, responded with applause and a burst of camera flashes.

But as the 196-wheel transporter idled there under huge spotlights befitting a city known for its star-gazing, the crowd poured off the sidewalk and moved toward the boulder that will soon be the latest addition to the museum’s art collection. They touched the rock, marveled at its size, posed for photographs and congratulated the workers who had overseen the complicated task of transporting a rock-turned-art from a quarry 60 miles away.

“As far as I’m concerned, it’s like the Pyramids,” said Sandy Martin, a retired television producer, who had waited nearly three hours for this moment on a warm night drenched in moonlight. “We’ll never see this again in our lifetimes. I cried when I first saw it.”