A sprawling tree-covered island in Canada has mysteriously disappeared weeks after it suddenly appeared, prompting locals and authorities to try to figure out its true nature and why it disappeared.

The strange island was spotted in British Columbia’s Williston Reservoir in July by a local boater, who took photos and shared them with local resident Rocky Avery.

The pictures spread quickly on social media, but the biggest question was where did such a big island come from?

Later satellite images also confirmed the existence of this island.

According to BC Hydro, satellite images from July 21 showed this unusual piece of land west of Finlay Bay.

According to officials, the island was about 230 feet wide and 460 feet long, which is about the size of 2 American football fields. The island was covered with trees and other vegetation.

However, when people looked at the site again in August, the island was not there, prompting speculation that it might have sunk.

According to a BC Hydro spokesperson, it’s possible the piece of land may have washed up on the beach or some other relatively safe area, meaning the island could still be out there somewhere.

One possible explanation, according to experts, is that the landmass may have become detached from the coast due to unusually high water levels, then blown out to sea by strong winds.

Rediscovering a floating island that has mysteriously disappeared due to its vast area has also become a difficult task.

BC Hydro says it’s looking for the strange piece of land, so it can be tracked down if it reappears.