The casino gun battle that left three bikers dead didn't do much to dampen the party mood at this quiet Colorado River town's second biggest tourist weekend.

The annual Laughlin River Run that drew thousands of motorcyclists to the Nevada desert 80 miles southeast of Las Vegas roared on with little interruption even as police investigated the deadly gunfight between outlaw biker gangs on the casino floor at Harrah's early Saturday.

``It's business as usual,'' said Del Newman, general manager of operations at the Riverside hotel-casino. ``The guests don't seem to be concerned.''

Motorcycle enthusiasts, estimated at 80,000 for the weekend, spent the final night of the event seemingly oblivious to the fatal melee between the rival Hells Angels and Mongols gangs.

Bikers compared vendor prices on jackets and helmets at parking lot booths as slot machines clanked out coins in the town's nine casinos, including Harrah's, which reopened hours after the shooting.

On the night of the brawl, thousands of beer-swilling fans rocked to the Doobie Brothers on the city's River Walk.

``It's normally a great time and it still is,'' said Craig Siems, a 45-year-old computer technician and Harley-Davidson rider from Orange County, Calif.

By Sunday, thousands of bikers were rumbling toward home, leaving investigators to sort out the bloody weekend.

Police said the trouble began when an argument between the Mongols and Hells Angels escalated.

``Blow by blow, stab by stab, and shot by shot, we know exactly what happened in that casino,'' said Las Vegas police Lt. Vince Cannito after investigators watched casino surveillance tapes.

Police also were trying to determine if the killing of another biker on the road to Laughlin was connected to the casino shooting. The victim was identified as Christian Tate, 28, of San Diego.

All three of those killed in the casino were gang members involved in the fight, said police, who did not release their identities.

Calvin Schaffer, 33, who is affiliated with the Hells Angels, was arrested Saturday on suspicion of murder, Cannito said. Police did not release his hometown.

After interviewing more than 500 people, police said they arrested three or four people on outstanding warrants unrelated to the shooting. More arrests are possible.

Police impounded about 100 motorcycles parked around Harrah's. They searched the bikes and confiscated weapons, including guns, knives and hammers, along with narcotics.

Officers said surveillance tapes show two members of the Mongols gang surrounded by several members of the Hells Angels as a fist fight breaks out and quickly escalates into a brawl involving as many as 70 people.

The tape shows one of the Mongols being shot.

``One of the Hells Angels guys pulls out a gun and pops him in the head, and after that it's just pandemonium,'' Sgt. Chuck Jones of the Las Vegas police department, which has jurisdiction in the town.

It was not immediately known if that victim was among those killed.

Area hospitals treated a dozen victims. Four were in fair condition, three men were in serious condition and a 47-year-old man was in critical condition.

Since 1983, motorcyclists enthusiasts have been roaring into this 8,000-person enclave each spring to show off their custom machines, party and fill the town's tills.

The five-day event, the largest bike rally in the West and fourth in the nation, is second only to New Year's Eve as the community's biggest draw.

``I think I'll come back because this could have happened in New York, in Las Vegas or Podunk, Iowa,'' said Chris Bonnema of Atascadero, Calif.