The speed limit on a 2-mile section of the Natchez Trace Parkway near Clinton will be reduced from 50 to 35 mph until April so biologists can monitor an endangered species of salamander, the National Park Service said.

The speed limit starts at South Norrell Road and the parkway in Bolton and goes north for 2 miles. South Norrell Road is south of the Clinton/U.S. 80 exit of Interstate 20.

The National Park Service is working with the Mississippi Museum of Natural Science, United States Geological Survey, and Millsaps and Mississippi colleges to monitor the amphibians.