By MARK FREEMAN

GRANTS PASS -- For years, Doug Smith would don the latest pair of quirky, spiked sandals his dad, Sherman, devised in the '50s and '60s, so his feet wouldn't slip off slick Rogue River rocks while fishing.

"Anytime he came up with one of his great ideas," Doug Smith recalls, "he'd strap them on me and send me out to the river."

But Sherman Smith might fall over now if he were alive to see how far his son has gone with this funky invention fit for fishermen's feet.

Korkers Inc. of Grants Pass is now a $1 million business with a firm foothold in the niche of footwear for those who work or play around slippery surfaces.

The company's metal-studded, felt-and-foam, over-the-shoe sandals are widely used by shipping-dock stevedores, loggers, roofers and public-safety workers when they need a grip on timbers, shake shingles, metal roofs or icy roads.

Korkers also are considered standard equipment for anglers wading in swift currents.

They now sell in well over 200 sporting goods and equipment stores nationwide. Cabela's, Bass Pro Shops and L.L. Bean -- three of the top sporting-goods catalog companies in America -- also carry the spiked sandals.

Together, they cover a far wider sphere than when Sherman Smith built a few pair for him and his fishing friends.

"You never gave it much thought back then, that it would turn into something serious," recalls Doug Smith, now 59. "But over time, we saw people using them and that they actually worked. It was like, gee, maybe there is something to this."

That something is safety, says Wally Ramsay, a Jackson County sheriff's marine deputy who has worn Korkers while wading rivers since the early 1980s.

"Wearing them, you do have an advantage of being more stable, and you need to use all your advantages," Ramsay says. "Footing is everything."

The sandal designs are simple.

High-quality rubber is molded to fit a boot bottom, then 60 half-inch metal studs with carbide tips are embedded in the rubber. Buckle straps or heavy laces lash the sandals to the boot.

They sell anywhere from $35 to $50 a pair and easily can last several years.

Their grip is remarkable. Roofers can sprint up steep pitches, and stevedores can jump safely from log to log while loading export ships as if they were wearing expensive leather "caulk" spike boots used by loggers.

That's the idea Sherman Smith first had when he began tinkering with the studded sandal concept in the late 1950s.

An attorney and avid angler, Smith was like many Grants Pass fishermen of the time -- he would wear a pair of loggers' boots while wading the slippery and treacherous Rogue.

River water caused the leather to crack. So Sherman Smith, ever the tinkerer, began designing the sandal spikes to strap onto the shoes.

"He'd have these plaster of Paris molds, everything," Doug Smith says.

In 1958, the first sandals came to be, with Sherman Smith making a few for sale at Grants Pass sporting goods shops.

One employee was hired to crank out the sandals, with Sherman Smith sticking with his law practice full-time.

They sold sporadically until 1960. During a trip to a Portland sport show, the sandals caught the eye of stevedores there, who began buying them for use while loading ships.

For years, one employee made a hundred sandals or so a year, mostly for local anglers and the stevedores, Smith says.

Then the name Korkers came to be.

In 1968, Doug Smith strapped on what has become the standard studded sandal and headed into the Rogue near Galice.

"My mother looked at them and said, `That's a real corker,"' Doug Smith says. "To my mom, if it was good, it was a `corker."'

The name stuck, but the business never expanded after Sherman Smith died in 1968. It puttered along past the death of Smith's mother, Mary Louise, in 1978.

In 1982, Doug Smith came back to Grants Pass from running a mortgage company in Sacramento to make something of Korkers.

He became president as well as the research and development unit, marketing department and the public affairs department, all the while refining the Korkers' design and expanding the varieties of sandals and studs.

The company now sells three kinds of sandals as well as felt soles and studded felt soles, all of which are assembled by less than a dozen workers in Grants Pass.

He has recently developed foam-bottomed sandals for metal roofing work and is now designing a foam-sole sandal with magnets to better grip metal roofing.

"It's a lot tougher than I thought it would be," he says. "At times, I've wanted to give it up, but I'm glad I've stuck with it."

Korkers will move about 35,000 sandals this year, their best year ever, Smith says. That by far eats the lion's share of the market, which is too small for Nike and too big for new fly-by-nighters, he says.

"It was just a fun thing for my dad and I to play with," Smith says.