Kevin D. Korenthal recovers following surgery at Henry Mayo Hospital.

Local cycling advocate and political activist Kevin D. Korenthal was recovering Monday at Henry Mayo Newhall Hospital in Valencia after sustaining major injuries in a head-on collision Saturday on Sand Canyon Road.

Korenthal was riding his mountain bike at about 10:30 a.m. when a 16-year-old boy in a Honda Civic turned onto Sand Canyon from Bear Divide and struck Korenthal, who catapulted over the car and landed on his head in the dirt.

The collision broke two vertebrae in his neck and one in his back but there does not appear to be any spinal cord injury, his wife Christine said.

Kevin Korenthal was in relatively good spirits when reached by phone Monday despite the broken neck and numbness in an arm and fingers.

“I’m just trying to keep a catalog of all the new changes to my body,” he said.

In 2004, Korenthal had his left leg partially amputated following a crash that occurred when he was driving a car at age 19. He’s now 40.

Saturday’s crash broke the remainder of his left leg and bent the steel rod inside it.

The steel rod in Korenthal’s amputated leg is bent at a nearly 45-degree angle following Saturday’s crash.

The crash also broke his right leg as well as his scapula (shoulder blade), right wrist, right tibia, right fibula and three ribs, Christine Korenthal said.

“Judging by his helmet, he landed on his head,” she said, explaining that gravel was embedded in the helmet.

Korenthal on a better day.

She said the young driver was traveling at 40 mph to 45 mph when he collided with her husband.

“I’ve got a new steel rod in my remainder leg and a first-time-ever rod in my full leg,” Kevin Korenthal said. “I’ve got a reduction of use of my left arm, and on my right hand, I can’t feel my fingers. With the addition of the broken neck, I’ve got some issues to overcome.”

Korenthal said he expects to be in the hospital about two more days.

Asked whether he’s going to get right back on a bike, he said, “Absolutely.”

As soon as he gets a new one.

Korenthal is owner of the local public relations firm KORE Communications. He started the Facebook group, SCV Trail Users, which advocates the opening of hiking trails to mountain bikes.

He also served on the Newhall Redevelopment Committee, ran for the Castaic Lake Water Agency board in 2010 and writes an opinion column that is published on SCVNews.com.