Highway workers used to scrape dead deer off the road and bury them, but now the State Highway Administration turns the carcasses into compost used to help grow roadside grass and wildflowers.

Recycling biodegradable material to improve the land along state highways is environmentally friendly and it saves money previously spent on digging graves and buying compost, said Jim Jones, SHA chief facility maintenance officer. SHA got the idea to compost the deer from West Virginia, where compost is made from hog carcasses, he said.

In 2001, the Maryland State Highway Administration opened a facility in Carroll County for collecting deer and allowing them to decompose. Since then, about 3,600 deer have become compost. In 2007, workers picked up 1,056 deer carcasses in Frederick County and 576 deer in Carroll County.

In April, another facility opened in Frederick County, a two-acre area behind the truck rest stop on eastbound Interstate 70.

At these facilities, highway workers drop deer carcasses into bins filled with sawdust and a mixture of horse manure and wood chips. As the carcasses decompose, the temperature of the compost pile is monitored. Once the temperature levels at 135 to 150 degrees Fahrenheit, the compost is mixed, allowing it to oxygenate.

The carcasses are mixed with wood chips from state-maintained trees and manure from local horse farms. The mixture is monitored for four to six weeks, until it reaches the right temperature.

The heat destroys any disease-causing bacteria, but since it does not get hot enough to kill rabies, animals that could carry that bacteria, such as foxes or raccoons, cannot be composted, Jones said. The carcasses of those animals are buried elsewhere.

After the compost reaches the optimal temperature, it is aerated to and moved out of the bin, and after several months in a stock pile, SHA can use it as fresh dirt.

“We feel it’s been a pretty good process,’’ Jones said. “It saves a little bit of time and effort.’’