Any career which involves regular contact with the "general public" includes situations which put the employee's sense of humor to a serious test. Those oft-envied park ranger jobs are no exception, as illustrated by the following story related to me years ago by a fellow ranger at Grand Canyon National Park.

A ranger working at an outlying location at Grand Canyon was on his way to an important meeting at Park Headquarters. He was all dressed up in his best "Class A" uniform, shoes shined and pants creased. About fifteen miles from headquarters, he came upon a pickup truck with a big slide-in camper mounted in its bed.

The rig was parked partially off the side of the road, and a woman was standing alongside, peering sadly at a flat tire on the left, rear wheel. A small child peered out of the open window of the truck. The woman looked up, spotted the ranger's truck, and began a frantic "Hey Ranger!" wave.

Well, what's a good ranger to do? He pulled over, sized up the situation, and quickly concluded that the anxious woman had no idea how to change the tire. Assuring her that he'd get some help, he called the dispatcher on his radio, hoping another ranger was nearby and available to help.

No such luck. A second request for the wrecker service at the Fred Harvey garage determined they were on another call, and wouldn't be available for an hour or more.

In the best Hollywood tradition, a line of ugly, dark clouds began to drift into view. Rumbles of thunder were clearly heard in the distance, and it was obvious a storm was brewing. The woman looked increasingly distraught, and right on cue, the child began to cry. The ranger suppressed a sigh, radioed dispatch that he would be late for the meeting, took off his coat, rolled up his sleeves and went to work.

The spare tire was stowed underneath the bed of the pickup. After thousands of miles on highways and byways, such tires provide a good record of every place the truck has been, especially if the vehicle has done any traveling off paved roads.

This one was a dandy, with several years' accumulation of caked and baked dirt and gravel. As a bonus, there was also a generous sampling of thoroughly dried weeds that had stuck to the tire before the mud hardened to the general consistency of concrete.

It's possible to date trees by counting the growth rings in the trunk. I'm told that it would have been possible to chronicle the travels of this camper by analyzing the numerous layers of dirt coating that spare tire.

Freeing a tire in this condition from the underside of a truck usually required that some unlucky soul crawl part-way under the vehicle and loosen enough of the petrified grime to allow the spare to be removed from the chassis. The trick was to position your body so you could reach the tire, but avoid having all the "stuff" you loosened fall directly onto your face.

Owners of current truck and SUV models can be grateful that an engineer in Detroit must have had a similar experience, because many newer models have a little winch cable that makes this job a lot easier. You just put the end of the tire tool through a hole near the back bumper, line it up just right, and rotate the tool to lower the spare tire to the ground. (That assumes you can find the secret compartment other engineers have cleverly designed to hide the tire tool and jack, but that's another story.)

Unfortunately for the ranger in our story, this was back in the good ol' days when a truck was a real truck instead of a sports-something named after an exotic location. This spare was bolted right to the frame of the truck, held firmly in place with a Bubba wing nut. Considerable persuasion was required to remove the nut, a process which also liberated most of the accumulated dirt from the bottom of the tire and nearby undercarriage.

Perseverance was finally rewarded, the spare was freed from its prison, the flat tire was removed and the replacement tire was mounted for service. The now thoroughly sweaty and very grimy hero was ready to lower the truck back to the ground, and put his hand on the jack handle. The timing was providential, as the first big drops of rain were just starting to fall.

The driver of the truck spoke up. "Please be careful, now, and let it down real easy."

The ranger was a little puzzled, since the woman had already asked him to "be careful" several times, and he thought he'd done so throughout the whole ordeal. He was at least gratified at her concern that he not get hurt in the process.

"Sure, I'll be careful."

"Good," the woman replied. "I wouldn't want the truck to bump when you let it down. That might wake up my husband. He's taking a nap inside the camper, and so far he's managed to sleep through all this!"

This story is adapted from the book Hey Ranger! True Tales of Humor and Misadventure from America's National Parks. © Jim Burnett and Taylor Trade Publishing, used by permission.