Yellowstone National Park officials now say some entrances could reopen "as early as this weekend" after historic floods hit Monday.

But, they say, "it is probable that road sections in northern Yellowstone will not re-open this season due to the time required for repairs."

Yellowstone's northern road loop includes the Grand Canyon of the Yellowstone, popular wildlife viewing areas in the Lamar Valley, and the Mammoth Hot Springs Lodge and park headquarters.

The southern road loop, which sustained less damage, accesses Old Faithful geyser, Yellowstone Lake and a major visitor center. But, Park Superintendent Cam Sholly says, "half the park cannot support all the visitation. So we are exploring a range of options."

Those include possibly a ticketed entry or reservation system. About 4 million people a year visit Yellowstone National Park.

Flood waters around the Park crested late Monday night. Flood warnings or watches remain in effect for several counties downstream on the Yellowstone river and its tributaries.

Just outside the park's north gate, the community of Gardiner saw limited road access restored yesterday after being cut off for around 24 hours after roads washed out Monday. Yellowstone Public Radio reports the main highway out of town is now open to incoming residents and essential goods only, and to outgoing visitors.

Sholly advised people to get out quickly. "Don't wait around and see if another event happens," he said Tuesday. "I would take advantage of getting out of here while you can."

Meanwhile, drinking water in Gardiner remains unsafe, forcing local businesses to adapt.

Stacey Joy, who owns a lodge and cafe in Gardiner, told YPR's Olivia Weitz that they are serving a limited menu and doing the best they can in the midst of a continued boil order.

"We usually have a line out the door for coffee and espresso, something that we cannot do right now," she said. "The water temperature is not at a temperature for long enough to make that water safe."

She said she's, "anxious to see what [the park's] plans are" for reopening the northern road loop and north entrance. It's the park's second most popular and the lifeblood of Gardiner's economy.

Joy marveled at, "just the devastation of the roads and bridges, who knows if the North entrance is going to be a viable option for tourism this year."

About 50 miles downstream, where the Yellowstone river runs through the town of Livingston, Mont., damage is still being surveyed.

"Everything is covered in a layer of mud," Montana Public Radio's Nick Mott reported as he helped a friend and her neighbors in Livingston clean up after water breached a layer of sandbags. "I am just standing in muck and mud right now."

Flood damage is "relatively isolated to areas near the river," Mott said. "But that's not an insignificant amount of space in Livingston - the city is oriented around the river."

The town's only hospital reopened Wednesday morning after being evacuated Tuesday. A post on the hospital's website says flood waters did not reach the building, though the system's phone lines remain down.

Further downstream, the water treatment plant in Montana's biggest city, Billings was knocked offline by floodwaters Tuesday night. The city of 117,000 has "between a day to a day-and-a-half of water supply for Billings."

Officials expect water levels to peak today, they need them to drop by about a foot for the plant to be able to operate again, but, "the plant still has the task of cleaning filters to properly operate." Residents are being asked to conserve water in the meantime.

Only one park gateway town remains cut off due to washed out roads–that's Cooke City at the northeast entrance to Yellowstone.

"We can't provide law enforcement services out there right now, public health services," Bill Berg, commissioner for Park County, Montana, told Jackson Hole Community Radio Tuesday. "We can't get out there to pick up the garbage. Some of this stuff is pretty basic."

At the bottom of the mountains in which Cooke City sits is the town of Red Lodge, much of which flooded and remains cut off from drinking water or under a boil order.

"What we're trying to focus on currently, right now, is travel routes at bridges and access. That's our number one concern," Carbon County Incident Commander Tom Kuntz said. "Our number two, [and] equally up there is water and sewer."

Kuntz was briefing Montana Lieutenant Governor Kristan Juras yesterday. Governor Greg Gianforte is currently out of the country and being criticized for not rushing home as the state struggled with historic flooding. His office now says he is returning "as quickly as possible."

Yellowstone Public Radio reports Kuntz said river levels continue to rise downstream of Red Lodge in Bridger and Fromberg. He added that snow melt remaining on the mountains combined with warm weather and more rain could lead to another flooding event. He said both conditions are forecasted for Saturday, but possibly to a lesser degree.

Since June 13th, Montana Army National Guard helicopters have rescued 87 people and flown more than 41 hours in support of search and rescue operations in south central Montana.

Among them, Katie Wise, a musician visiting from Colorado, who was rescued from East Rosebud and brought to an evacuee center in Red Lodge.

"I'm pretty adrenalized right now. My heart is pounding," she said. "The most stressful part was that we didn't know the helicopters were coming, so we were just talking about how we were going to do the whole water and rationing food, and we were going to do a food inventory and gather back as a community.

Across Montana at least a dozen counties are are under flood warnings or watches today and tomorrow, primarily along the Yellowstone River. But far to the north, the flood warning for areas around Glacier National Park is in effect "until further notice."