The Super 8 Motel in Estes Park was ranked No. 8 on the list. The list was created based on travelers' experiences.
Some visitors who wrote on TripAdvisor.com said, "I wouldn't let my dog sleep here," and "It's a total dump!"
"We have a good motel," Mary Chung, the motel's owner, told 9NEWS.
Chung and her husband Vincent have owned the motel for more than two decades.
Visitors have complained about dead plants, mold in the bathrooms and even rodent feces.
"Sometimes it does happen," Chung said. "We thought we do have pretty good house cleaning to clean the rooms."
Chung says she and her husband have had several conversations with the motel's maids and asked them to take better care of the rooms.
She says the rooms are inspected and cleaned every time someone stays there.
In 2010, Chung says she only received 10 complaints. On TripAdvisor.com there were more than 30.
"Sometimes people complain to get discounts or free rooms," Chung said.
Chung and her husband say being on the list is embarrassing and they plan to do whatever it takes to make their motel more "visitor friendly."
This is the sixth year the company has complied the list. TripAdvisor.com says New York City's repeat offender, the Hotel Carter, has made the dirty hotel list for five of the last six years.
TripAdvisor.com's 2011 Top 10 Dirtiest Hotels in the U.S.:
1. Grand Resort Hotel & Convention Center - Pigeon Forge, Tennessee
2. Jack London Inn - Oakland, California
3. Desert Inn Resort - Daytona Beach, Florida
4. Hotel Carter - New York City, New York
5. Polynesian Beach & Golf Resort - Myrtle Beach, South Carolina
6. Atlantic Beach Hotel - Miami Beach, Florida
7. Rodeway Inn - Williamsville, New York
8. Super 8 Estes Park - Estes Park, Colorado
9. Palm Grove Hotel and Suites - Virginia Beach, Virginia
10. Econo Lodge Newark International Airport - Elizabeth, New Jersey
(KUSA-TV © 2011 Multimedia Holdings Corporation)