CHAFFEE COUNTY - Two Denver-area men died rafting Tuesday on the most advanced section of the Arkansas River. The private, four-person party was on the Pine Creek Rapids - between Granite and Buena Vista, about a mile up river from the Numbers - when their boat flipped, according to reports from Colorado State Parks and the Chaffee County Sheriff's Office. "That section's been cut off for quite some time ... We've been out of it for a couple weeks," said Duke Bradford, chairman of the Colorado River Outfitters Association, which represents about 50 licensed rafting groups. The men who died in Tuesday's accident - which occurred at about noon - had been in a raft with another man and a woman. The people in the raft pulled one of the men out of the river, but were unable to revive him.The second man was washed about seven miles down river before he was pulled out. Rescuers couldn't revive him. The two men's names have not been released, according to The Associated Press.Bradford said Pine Creek Rapids (Class V) has been running at about 1,800 cubic feet per second; the cut-off is 1,250 - as recommended by the Arkansas Headwaters Recreation Area. The Pine Creek "hole" (a river drop over a rock or ledge that circulates with potential to trap a person) in the center of the rapids "becomes the issue that warrants the cut-off level," he said. "It could have gone wrong anywhere in that rapid," Bradford said. "The entrance is particularly spicy. There are a couple holes along the top right side that are considerable."Deb Frazier, spokeswoman for Colorado State Parks, said the rafting deaths Tuesday were the only ones to occur this year on the Arkansas River.Bradford said Pine Creek is one of the river's least popular sections, in part because of the danger."If 1,000 boats went down river on the Arkansas, 10 would be on Pine Creek," he said.He said Tuesday's accident is "unfortunate" and a "tragedy." "It's important (that) people understand the section of river at the time they're running it," he said.Though Pine Creek reaches cut-off beyond 1,250 cfs, others handle much higher flows before AHRA recommends cut-offs. The Numbers (Class IV-V) is cut off at 2,400 cfs and the Royal Gorge (Class IV-V) at 3,200 cfs. The Pine Creek section drops more than 200 feet in less than a mile, while the Numbers and Royal Gorge drop 75 and 55 feet per mile, respectively.Rapids range in difficulty from Class I to Class VI. A Class V (expert) rapid includes extremely long, obstructed or very violent rapids that may contain "large, unavoidable waves and holes or steep, congested chutes with complex, demanding routes," according to americanwhitewater.org. Robert Allen can be contacted at (970) 668-4628 or email@example.com.