Mike Lees has become an amateur paleontologist after an impromptu pee break in Edmonton's river valley last month led to the discovery of a petrified tree stump estimated to be from the time of the dinosaurs.

"We pulled over at a very inopportune spot for an emergency pee, and this is how we came across this particular item," Lees said in an interview Wednesday with CBC Radio's Edmonton AM.

"It's the whole base of a tree stump. I'm no archeologist or paleontologist. The only reason I discovered it is because I almost peed on it."

"You count the rings in the tree, and that's how I knew it was a tree and not a rock, even though it looks like a rock and sounds like a rock."

Lees and a friend were paddling on the North Saskatchewan River in October when nature called.

As they pulled their canoes onto the bank, something caught Lees's eye. A video of the encounter captured his unfiltered excitement.

'This is a tree, dude'

"I've never seen this before. This is a tree, dude. It's f--king stone," Lees said at the time. "It's a fossilized f--king tree, man.

"Look at these layers. This is bark. This is f--king bark. This has probably been under here forever and ever and ever."

Lees sent photographs of the fossil to researchers at the Royal Tyrrell Museum in Drumheller, Alta. Paleontologists there estimated the stump was at least 65 million years old, he said.

"I would have never expected to find something like this. It's exciting," Lees said.

"There are portions of the river in downtown in Edmonton that are really untouched, and it's a gold mine for fossils and all sorts of neat things."

Despite its age, researchers were not keen to orchestrate their own excavation of the rock. Due to erosion over the decades, it has moved from its original location, making it less scientifically valuable.

However, if Lees and his friends manage to remove it, researchers at the University of Alberta would be keen to have it, he said. He hopes the fossil ends up on display at a museum for the public to see.

The Royal Tyrrell Museum of Palaeontology was called about the fossil last month, said spokesperson Elaine Secord.

"Experts at the University of Alberta provided us with their expert opinions, indicating that the stump was no longer in original stratigraphic position nor was it of high scientific value," Secord said.

"Since this fossil was no longer in its original context … there was no legal objections to him removing the fossil from where he found it."

Lees and his friends have tried repeatedly to remove the fossil but so far have been foiled by its weight. (Submitted by Mike Lees)

Petrified wood — wood turned into stone through mineralization — is common in Alberta, but like any paleontological find, there are rules around collecting it.

Under Alberta's Historical Resources Act, fossils cannot be removed from a provincial park, national park or designated protected area.

Removing petrified wood on public lands is also not allowed, unless it's clearly visible on the surface of the ground and a permit is obtained from the provincial government.

Boat and barge used to extract stump

The stump will officially remain the property of the Crown, but Lees has attained the permit to move it.

However, there is a problem. The one-metre stump is heavy — really, really heavy.

"I'm guessing it's a couple thousand pounds for sure. We tried to pick it up, and we failed."

Lees and his friends have staged multiple attempts to extract it. The first attempt involved a large hunting boat. A second attempt involved a barge made of rain barrels and a crew of six men.

At this point, in order to extract it, a helicopter would probably be best.​​​​​ - Mike Lees

Lees plans to build a bigger barge but with winter on the horizon, he's running out of time. He fears the stump may disappear as the river freezes this winter and then floods next spring.

"We have a professional group that's going to come in with a barge and some machinery that's needed in order to lift it properly and not sink the ship at the same time.

"At this point, in order to extract it, a helicopter would probably be best."