The body of 29-year-old Jetal Agnihotri was discovered Monday in Zion National Park where she'd been hiking with friends on Friday before going missing that evening. Park officials say she ended up near some sandstone cliffs, known as the Court of the Patriarchs along the Virgin River ... rather far from her last known whereabouts.

Agnihotri had stayed behind when a downpour hit Zion, wanting to explore the Narrows before meeting up with her group. The Narrows is a popular hike, where people are often knee-deep in water as they traverse the winding trail within the park's canyons.

When she didn't show at a rendezvous, her party notified staff ... and a multi-day search got underway with upwards of 170 professionals fanning out to look for her -- an effort that included search dogs. Now, an autopsy will be done to determine her cause of death.

Her family has told local media they believe her being carried away by an extremely powerful current was actually captured on camera by another group of hikers further down the trail in the Narrows.

The clip shows two people -- a man and a woman -- floating in debris-filled water that's at an incredibly high level. The woman is barely visible, almost slumbered entirely as people scream and look on.

Agnihotri was eventually found 6 miles from where she went missing ... so it would seem she was taken downstream quite a ways. That's how strong the water can get there, especially during monsoon season ... running from July through September at Zion.

The woman was a graduate student at the University of Arizona, and was expected to start school again in the fall.