YELLOWSTONE NATIONAL PARK (AP) — Throngs of tourists gleefully watched the legendary Old Faithful geyser shoot towering bursts of steaming water while others got stuck in “bison jams” on picturesque valley roads as visitors returned Wednesday for the partial reopening of Yellowstone National Park after destructive floods.

Park managers raised the gates at three of Yellowstone’s five entrances for the first time since June 13, when 10,000 visitors were ordered out after rivers across northern Wyoming and southern Montana surged over their banks following a torrent of rainfall that accelerated the spring snowmelt. The cost and scope of the damage is still being assessed, Yellowstone Superintendent Cam Sholly said Wednesday.

Empty roads and parking lots quickly grew busier by mid-morning as about 5,000 vehicles entered the park after getting through long lines that stretched for several miles at one gate in the early morning. The backups were gone by early afternoon, though, and visitation numbers were less than a normal summer day that draws about 10,000 vehicles, park officials said in a news release.

Paul Nithyanand of Chennai, India, gathered around Old Faithful along with 1,500 people in the afternoon to see it erupt. Nithyanand was touring the western U.S with his brother and had already seen the Grand Canyon and Las Vegas, but said nothing on his trip compared with Old Faithful.

“It’s awesome,” said Nithyanand, who was so impressed he waited around 80 minutes to it erupt again. “I’ve been seeing it in movies and on YouTube but seeing it live is amazing.”

Lonnie and Graham Macmillan of Vancouver, Canada, were among those at a so-called “bison jam” where a group of the burly animals crossed the road. The bison sighting capped a successful morning in which they’d already seen two moose and numerous deer.

They showed up at the park last week, only to get turned away as it was under evacuation. They diverted to Mount Rushmore in South Dakota for a few days and then to Wyoming’s Big Horn mountains before returning to Yellowstone as soon as the chance arose.

“The whole purpose of our trip was to come here,” Lonnie Macmillan said. “We weren’t going to go home until we got here.”

Tiffany Jahn from Kenosha, Wisconsin, who was with her husband and daughter in the line at the south entrance in Wyoming, said she was excited to see anything that was still open and especially hoping to glimpse the park’s wildlife.

“We were actually coming last week and we were getting messages ... saying ‘Don’t come, don’t come,’” she said. “But we were already out here so we kind of just altered our plans and made it work. ”

The record floods reshaped the park’s rivers and canyons, wiped out numerous roads and left some areas famous for their wildlife viewing inaccessible, possibly for months to come. It hit just as a summer tourist season that draws millions of visitors was ramping up as the park celebrated its 150th anniversary a year after it tallied a record 4.9 million visits.

Some of the premier attractions at America’s first national park were again viewable, including Old Faithful, which shoots bursts of steaming water almost like clockwork more than a dozen times a day.

But the bears, wolves and bison that roam the wild Lamar Valley and the thermal features around Mammoth Hot Springs will remain out of reach. The wildlife-rich northern half of the park will be shuttered until at least early July, and key routes into the park remain severed near the Montana tourist towns of Gardiner, Red Lodge and Cooke City.

The reopening comes as officials in Yellowstone are still tallying the extent of the damage. Based on other national park disasters, it could take years and carry a steep price tag to rebuild. It’s an environmentally sensitive landscape with a huge underground plumbing system that feeds into the park’s geysers, hot springs and other thermal features. Construction season only runs from the spring thaw until the first snowfall, a narrow window that means some roads could receive only temporary fixes this year.

That’s turned some Montana communities into dead ends instead of being gateways to Yellowstone, a blow to their tourism-dependent economies. They’re also still struggling to clean up damage to several hundred homes and businesses that were swamped by flooding.