The Ohio River, one of the nation's most important inland commercial waterways, has succumbed to the cold.

The river, frozen bank-to-bank for the first time since 1948, complains with sudden cracks and long low groans about its unaccustomed burden of ice.

Iceboats, uncommon sights at this latitude, skim the surface, their runners screaming. Dervishes of snow dance around them.

Groups of adventurers, bundled against the sub-zero temperatures and looking like figures in a Currier and Ives print, trudge across the ice toward Indiana; someday they will tell their grandchildren about the freeze of '77.

Overhead, a police helicopter hovers, the downdraft from its blades causing the wind-chill factor to nosedive. An officer with a bullborn warns that a fall through the ice means sure and sudden death. But the people will not be shooed to shore. They trudge on determinedly, pursing a memory.

Commercial traffic on the Ohio has come to a virtual standstill. Towboats and barges, unable to ram through the thickening ice, have been tied up along the river's banks to await a thaw. Their cargoes of oil, steel, coal industrial chemicals and de-icing salt grow more precious.

Along a riverside roadway, drivers pull over to the side and gawk at the unmoving Ohio. It is as if the river startling natural phenomenon. No longer can it be taken for granted as a carrier of sewage, or as an acquatic interstate highway for tows and tankers, ot as a summertime playground. Now it is the awesome and beautiful river it always was.

Old-timers warm themselves at a driftwood fore and swap memories of the ice gorges of 1911 and 1936, when ice choked the river for months. In 1911 the Ohio was crossed by an ice dam 75 feet high that withstood extensive dynamite blasting by the Army Corps of Engineers and blocked River traffic for weeks. It was also in that year that an Indiana butcher bought 43 hogs in Kentucky and drove them across the ice.

Current conditions on the Ohio do not warrant close comparison to such famous freezes of the past, but continued sub-freezing temperatures on the river could create the "gorging effect" that causes the ice to mount. Bottom layers of the water freeze, to be lifted by the River's flow. Layer is stacked upon layer until the beginnings of an ice mountain start to rise over the surface.

The countless daredevils - including whole families - who are venturing on to the ice for a bank-to-bank walk ignore oficials' warning s that an accident would almost certainly prove fatal.

One problem is that there is still some traffic on the river. The largest tows can still break up the ice and negotiate the river channel near Louisville. Their passage thus sets a trap for the umwary.

One family walked across the river just two hours after a towboat passed through the channel, breaking the ice near the middle of the river into small chunks.

River authotities, including spokesmen for the U.S. Army Corps of Engineers and local police, warn that a fall through the ice would almost certainly result in death. The river's current would suck an unfortunate victim under the ice and whisk him downstream. If he were lucky enough to find a pocket of air beneath the ice, which would save him from drowning, a victim might live three to five minutes until exposure resulted in death.

Despite the warnings, people continue to try the river in large numbers.

"There's nothing we can do about it," said a local police oficial. "There's no law against walking on the river ice. And, there's no law against stupidity."

The Corps of Engineers says river traffic near Louisville has all but stopped. A few large vessels are still able to battle their way through the ice, but trafic is less than 10 per cent of normal for this time of year.

According to the corps, the greatest danger would be occasioned by a sudden thaw, which would send car-sized floes hurtling downstream on a current made stronger and swifter than normal by tons of melting snow and ice.

A quick thaw would scour the stream's banks, endanger riverside structures and docked pleasure craft and would threaten all the commercial vessels that have been forced to tie up at the river's banks. Such a thaw would also give rise to flooding conditions along the Ohio and the Mississippi, into which it flows.