A family walking on a trail in Texas this weekend made a startling discovery when they spotted an abandoned newborn baby wrapped in a towel.

The baby found Saturday evening was “freshly born” with remnants of the umbilical cord still present, authorities said.

The family immediately called emergency officials.

The baby was in stable condition at a hospital in Katy, Texas, the Harris County Sheriff’s Office said on Saturday.

An “unknown male” had left the baby on a small bridge, the sheriff’s office said, but they did not yet have a suspect.

Around 9:00 local time, Daniela Fedele was walking on the trail with her husband, three-year-old daughter, and their dogs when she spotted something.

“I noticed two little feet moving…and I yelled to my husband, ‘Oh my god, a baby, a baby!’” Ms Fedele told local television station KHOU. Her husband quickly shouted to call emergency services.

She said they rushed to pick up the baby and found some shade. Weather forecasts in the area show temperatures that day reached a high of 96F (35.5C).

“This image has been going on through my head so many times,” Ms Fedele said. “How can you do that?"

Texas’ Safe Haven Act, also known as the Baby Moses Law, allows parents who feel they cannot take care of their baby to bring it to a fire station, hospital, or emergency medical services station. Babies surrendered under the law must be 60 days old or younger and unharmed.

The sheriff's office said after the baby was examined and treated by doctors, Texas’ Child Protective Services agency would step in.

The individual who abandoned the baby could face charges of abandoning and endangering a child.