Officials say the women were driving a white four-door Chevy Silverado truck and dumped eights cats in two small, dirty crates outside the shelter Tuesday morning.
A pit bull mix pup was also seen jumping out of the vehicle, but the women managed to retrieve it.
"I know that it probably stems from desperation on their part of the people dropping them off, or they don't want to come in and maybe face us," said Barb Hutchinson, executive director.
Dumping animals is nothing new.
One shih tzu was left tied to a pole out front one morning with temperatures in the 40's and was repeatedly doused with water as the sprinklers came on.
Other times, employees come to work only to find a string tied to the front door with a collar attached to it.
"I would really like it if people would come in and talk to us about the cats, tell us the problem," she said. "We want to work with people. We want to help. We're here for the animals." (Photos of the Cats >>>)
In Idaho, it's illegal to abandon an animal without making provisions for its care.
The image in the video is too blurry to get the license plate so it is doubtful that the cat dumpers will be caught.
"The weather is getting colder," CCAS officials posted on Facebook. "Dumping animals outside is cruel."
CCAS says it will always do its best to work with people who have animals they cannot care for, but with no background information on the animals, it makes it harder to find appropriate, loving homes.