Lots of folks get into trouble in the Great Outdoors by making assumptions, a term closely related to "speculate," "bogus," and "imagine." As the following story illustrates, when you’re faced with a choice that could determine whether your day turns out to be fun or frantic, none of those is a great basis for a decision.

A man I’ll call Mo and his wife Flo set out on a four day canoe trip on the Green River in Utah's Canyonlands National Park. The couple, in their mid-40s, were not amateurs on the water. Mo was a canoe instructor and experienced outdoorsman. He had made this same trip before, so we might be tempted to assume he’d be capable of making good decisions. If we did, we’d be guilty of some bogus speculation.

A little background about the terrain will help set the stage for the story. This area of colorful rocks and sweeping vistas is remote and rugged, with limited road access to the rivers in these desert canyons. The Green and Colorado Rivers both flow in a generally southerly direction across eastern Utah until they join forces in the heart of Canyonlands National Park. The official name for the intersection of those two famous rivers is the Confluence.

As described in a park publication,

“Both rivers are calm upstream of the Confluence, ideal for canoes, kayaks and other shallow water craft. Below the Confluence, the combined flow of both rivers spills down Cataract Canyon with remarkable speed and power, creating a world-class stretch of white water. . . . Cataract Canyon contains fourteen miles of rapids ranging in difficulty up to Class V. It is a particularly hazardous and isolated section of the Colorado River and is subject to extreme water level fluctuations.”

For the benefit of non-whitewater readers, a rating system for rapids ranges from Class I (easy even for novices) to the extremes of Class VI (don’t even think about it). The Class V rapids in Cataract Canyon are thus very challenging indeed, and are described as “Expert. Extremely long, obstructed, or very violent rapids which expose a paddler to above average endangerment.”

Given the above information, a prudent person would not make any assumptions about a trip through Cataract Canyon. This is a stretch of river for experienced boaters only, and those who are not prepared to run that “world-class stretch of white water” simply end their trip down either the Green or Colorado at the Confluence. There is no road access to that point, but several private companies offer a shuttle service via jetboat back up the Colorado River to the town of Moab.

Mo and Flo had prudently planned to end their trip at the Confluence and utilize that shuttle service after covering fifty-two miles of the Green River during their four-day float. When the pair arrived at the Confluence, they somehow mistook that joining of two major rivers for a much different location: the junction of the Green River with the abandoned channel of that same waterway at a spot named Anderson Bottom.

That’s a serious oops in the navigational department, since Anderson Bottom is thirty-one miles upstream from their actual location at the Confluence.

As a good example of your tax dollars at work, the National Park Service has done its part to try to prevent such errors, and ensure that boaters avoid an unplanned adventure—or an untimely end—in Cataract Canyon. A large sign has been placed in this area to warn visitors about the dangerous rapids 2 1⁄2 miles ahead in the canyon. This advice to reconsider and turn back before it’s too late would be the government’s more prosaic version of the line from Dante’s Inferno, in which a sign at the entrance to Hell reads, “Abandon hope, all ye who enter here.”

You might be tempted to think most people would read that sign and consider carefully before continuing downstream. Our duo apparently did stop and consult their map, but since they had already misidentified the Confluence of the Green and Colorado Rivers, they were still convinced they were over thirty miles back upstream from their actual location.

Alas, they were on the slippery slope of Assumption-land, where it becomes increasingly easy to allow imagination or wishful thinking to overcome logic. Since there were certainly no major rapids only 2 1⁄2 miles downstream from their assumed location, how might they reconcile that fact with the contradictory information on the sign?

Apparently the answer seemed pretty easy at the time. They speculated that the sign was supposed to warn about dangerous rapids 32 1⁄2 miles ahead, and that vandals had removed the initial number “3,” thus changing “32 1⁄2” miles into “2 1⁄2.” Once the inconvenient matter of a missing thirty miles was resolved, our intrepid pair continued downstream.

The official report does not record the conversation between the couple, so the following dialogue is simply conjecture on my part (not to be confused with assumption). Shortly after resuming their float downriver, they heard what must have been an unexpected and unsettling sound.

Perhaps Mo asked, “Do you hear that noise?”

Mayhap Flo replied, “You mean that loud roaring sound?”

“Yeah,” said Mo. “The one that reminds me of Niagara Falls.”

What they heard was “Brown Betty,” the first of the major rapids referred to on the supposedly “vandalized” sign not too far behind them. They were unable to get their canoe to shore, but the couple did make one vital, life-saving decision. They quickly donned their life jackets, which I'd humbly suggest they should have been wearing for the entire trip.

Shortly after it entered this major rapid, the canoe capsized and dumped both occupants into the very cold water. They managed to survive the float through “Brown Betty” and two additional rapids before they were able to swim to shore on opposite sides of the river.

In an outcome bordering on the miraculous, Mo and Flo were uninjured and able to hike 3 ½ miles back upstream, where they encountered a motorboat being operated by a river tour company and were rescued.

The canoe with their food, water and other gear, an investment of about $2,100, continued downstream. Perhaps their stuff was scavenged for eventual sale on eBay by those same vandals who lurked in the canyon and removed numbers from warning signs in hopes of luring boaters to their doom.

That's not an assumption...just speculation.

This story is adapted from the book Hey Ranger 2: More True Tales of Humor and Misadventure from the Great Outdoors © Jim Burnett and Taylor Trade Publishing, used by permission.