The massive search-and-rescue effort after the recent floods in Colorado has been one of the biggest in state history – and the largest in the USA since Katrina – as thousands of stranded people are plucked from swirling floodwaters by helicopters or rumbled out of washed-out neighborhoods by all-terrain military vehicles.

TV and camera-phone images of people hoisted by helicopter from flooded homes have brought eerie comparisons with similar efforts to rescue stranded Gulf Coast residents during Hurricane Katrina in 2005.

The rescues in Colorado were only a fraction of the number in the Gulf – 3,101 Coloradoans as of Thursday, compared with 60,000 rescued from rooftops and flooded homes in Katrina’s aftermath – but the event still tested Colorado’s emergency-response system and brought together the assets of several agencies in challenging terrain.

Unlike the Katrina rescue effort, where critics later pointed to a breakdown in communication among local, state and federal agencies, various rescue teams in Colorado – from Colorado National Guardsmen to U.S. Forest Service Hotshot Crews – worked quickly and, by most accounts, effectively together in one of the largest rescue missions in Colorado history, says 1st Lt. Skye Robinson, a Colorado National Guard spokesman.

Six people have been confirmed dead since the floods began Sept. 11, and 140 are still unaccounted for, according to the Federal Emergency Management Agency.

“The assets needed arrived and were prepared and went out to mission,” Robinson says. “The process went very smoothly. This is how things should work.”

A major reason: experience from a series of devastating wildfires that mauled Colorado just two months earlier, he said. During those fires, which claimed two lives and more than 500 structures, some of the same agencies shared airspace and staffed emergency management offices together. Instead of rescuing residents, though, they were dropping cubic tons of water on the fires.

“We’ve worked with these people before; we know each other’s names,” he says. “They were able to walk in and get straight to work.”

In some of the most dramatic rescues, crews airlifted 85 elementary schoolchildren and 14 adults from an outdoor education session when roads were choked off. Then, more than 50 National Guardsmen, rescuers and residents needed to be airlifted out of Lyons when they became stranded by rising water.

“We had a lot of rescues from the air and from our ground operations, too,” says 1st Lt. James Goff, a National Guard spokesman.

Post-Katrina rescue efforts were led by the Coast Guard, which was faced with a dual disaster: first the punishing winds of a hurricane, followed by a massive urban flood as the levee system protecting New Orleans collapsed, says Scott Price, a Coast Guard historian. Around 5,600 Coast Guardsmen used HH-60J Jayhawk helicopters and tender boats to help rescue or evacuate 34,000 residents, often hacking them out of their attics with small crash axes, he says.

That was the largest Coast Guard rescue effort since the 1937 Mississippi River flood, when 67,000 people needed saving.

In Colorado, as the floods intensified, a federal disaster declaration launched inter-agency rescue teams – known as “Urban Search and Rescue Teams” – into the water-wrecked areas of northern Colorado, says Ricardo Zuniga, a FEMA spokesman on the ground in Colorado.

The teams consisted of about 80 rescue crewmembers with varying skills, from medics and bridge engineers to seasoned firefighters, Zuniga says. Ferried by military Chinook helicopters or light medium tactical vehicles (LMTVs), the crews were dispatched to the hardest-hit counties, he says.

More than half the rescues were in Boulder County.