Williamson County held humans for at least 11,200 years.
In recent times, a prehistoric skeleton was found in Williamson County.
The name of the skeleton is Leanderthal Lady.
The town of Leander is named after the skeleton.
Leanderthal Lady was found after the Texas Department of Transportation found remnants while drilling core/dirt samples for a new highway.

Native Americans also lived in areas of Williamson County.
The Tonkawa tribe lived in parts of the county.
Other tribes lived in the area.
These tribes included Kiowa, Yojuane, Tawakoni, and Mayeye Native Americans.

On September 1921, the remains of a hurricane moved over Williamson County.
The rains fell over Thrall, Texas.
The town received 39.7 inches of rain in 36 hours.
The storm killed 87 near Taylor, Texas, and 93 in Williamson County.
A total of 215 deaths were reported due to the rains.

On 27 May 1997, Williamson county had a tornado outbreak.
The county had several tornadoes during the day.
An EF-5 tornado (rating determined on the Fujita Scale) struck Jarrell, Texas, killing 27 persons.
An EF-3 tornado also struck Cedar Park, with one indirect death.
Williamson County held humans for at least 11,200 years. In recent times, a prehistoric skeleton was found in Williamson County. The name of the skeleton is Leanderthal Lady. The town of Leander is named after the skeleton. Leanderthal Lady was found after the Texas Department of Transportation found remnants while drilling core/dirt samples for a new highway.
Native Americans also lived in areas of Williamson County. The Tonkawa tribe lived in parts of the county. Other tribes lived in the area. These tribes included Kiowa, Yojuane, Tawakoni, and Mayeye Native Americans.
On September 1921, the remains of a hurricane moved over Williamson County. The rains fell over Thrall, Texas. The town received 39.7 inches of rain in 36 hours. The storm killed 87 near Taylor, Texas, and 93 in Williamson County. A total of 215 deaths were reported due to the rains. 
On 27 May 1997, Williamson county had a tornado outbreak. The county had several tornadoes during the day. An EF-5 tornado (rating determined on the Fujita Scale) struck Jarrell, Texas, killing 27 persons. An EF-3 tornado also struck Cedar Park, with one indirect death.
Williamson County, Texas