Waterfalls that had dwindled during an unusually dry January roared back to life this week in Oregon’s largest state park after days of heavy rain, delighting visitors eager to catch a glimpse of the cascades.

The popular Trail of Ten Falls at the park, Silver Falls State Park, near Salem, sends hikers on a meandering, 7.2-mile journey through a lush forest. The trail’s 10 thunderous plunges were supercharged this week as water poured into the Cascade Mountains, and they were joined by a dozen new waterfalls that have popped up.

“There a lot of ephemeral waterfalls that just showed up after the rain,” said Matt Palmquist, a ranger at the park. “It’s like walking through an enchanted forest.”

Silver Falls State Park draws over a million visitors annually to its more than 9,000 acres in the foothills of the Cascade Mountains. It’s an especially rainy corner of the Pacific Northwest as storms unleash heavy rain when they move up and over the mountain range. The park records about 80 inches of rain annually on average, Mr. Palmquist said. Salem, only 25 miles northwest, gets half that per year.

This year, though, has been drier than usual across the Pacific Northwest, with few storms in January.

“Most of the rain happened early in the month, and then we were basically dry,” said Hannah Chandler-Cooley, a meteorologist with the National Weather Service office in Portland, Ore. “We had some good stretches of sunshine in there.”

February finally brought significant rain to the Pacific Northwest with a series of back-to-back storms. Several areas near the park broke or nearly broke same-day rainfall records over the weekend when an atmospheric river hammered the region. A second storm hit on Monday and brought more rain as well as strong winds that knocked out power to tens of thousands of people in Oregon and Washington.

Silverton, a town close to the park, recorded only 3.26 inches of rain last month compared with the 6.70 inches it measures on average in January. It has recorded 5.6 inches of rain since Feb. 1.

While most visitors go to the park in summer, Mr. Palmquist said winter was the best season because that’s when the waterfalls have the biggest flows. Many of the country’s biggest waterfalls, such as those in Yosemite, peak after the snow melts in spring, but the falls in Silver Falls State Park are fed by winter rains, because the park sits at a lower elevation, about 1,300 feet.

In winter, after a storm like the one last weekend, the cascades of water grow so large that anyone who wants to take in the park’s most popular experience — that is, standing behind a waterfall — is bound to get wet.

Of the park’s 10 big waterfalls, there are four, including the 177-foot-tall South Falls, that visitors can walk behind. “After these big rains, it’s like walking through a carwash,” Mr. Palmquist said.

The big, gushing waterfalls make for spectacular photos and images, and videos of them appear all over social media. The ephemeral falls, the slight flows of water running down rocky hillsides blanketed in moss, feel like a secret.

“They’re really difficult to photograph,” said Matt Vahle, a photographer based in California. “They’re smaller.”

In some cases the fleeting falls are too far from the trail to capture without a special lens. Others are nearly right on top of you.

“You’d be walking down the trail and you could stick your hand out and there would be a 15-foot waterfall right there,” Mr. Vahle said.

Mr. Vahle visited the park Saturday during a photography trip to Oregon when the rain was pouring down. Walking along the Trail of Ten Falls, he saw the ephemeral falls forming right before his eyes.

“These little falls popped up everywhere,” he said. “They were coming up out of the rocks. There’s a bridge you cross, and when you look out over the bridge you can see three or four of these little mini-waterfalls coming out.”