Amid rising gasoline prices and increasing demand for alternative sources of energy, U.S. automakers are turning to natural gas to power new pickup trucks.

On Monday, General Motors Co. announced plans for a bi-fuel 2013 Chevrolet Silverado and GMC Sierra 2500 HD, which shift  between compressed natural gas and gasoline fuel on a six-liter V8 engine. And The Wall Street Journal reported that Chrysler Group LLC will unveil plans Tuesday for its first production-line bi-fuel Ram pickup trucks.

The bi-fuel Chevy Silverado and GMC Sierra provide customers with choices in advanced propulsion technology, and because CNG is a clean-burning, domestically produced fuel, it has wide appeal, said Ed Peper, the general manager of GM's fleet and commercial operations. The addition of a full-size bi-fuel pickup truck to GM's fleet portfolio is another milestone in putting the customer first in everything we do.

The announcements come at a time when U.S. gasoline prices have reached all-time highs for so early in the calendar year. The national average of gasoline prices stands at $3.74 a gallon, as unsettling tension with Iran and fears of a second recession in debt-stricken Europe continue to drive futures prices up.

President Barack Obama has set a goal of 1 million electric vehicles on U.S. roads by 2015. But during his State of the Union speech in January, he also advocated exploring all alternative energy options, including natural gas.

We have a supply of natural gas that can last America nearly 100 years, Obama said. My administration will take every possible action to safely develop this energy. He added that developing the energy would create and support more than 600,000 jobs by 2020.

GM said its bi-fuel pickup trucks will have a range of 650 miles with both options, but the company didn't specify the ranges for each fuel. It will build the trucks in its Fort Wayne, Ind., plant and send them to a supplier who will install compressed natural gas components for the bi-fuel delivery and storage system. They will be available for order beginning in April, GM said.

Joyce Mattman, the director of GM's commercial product and specialty vehicles division, says the company's new options should attract consumers weary of high gas prices.

The bi-fuel truck provides businesses with added re-fueling flexibility and eases consumer range concerns that typically come with CNG, all while reducing emissions and controlling costs,  Mattman said. This turnkey ordering process, combined with the best warranty in the industry for a commercial product, makes our bi-fuel truck an attractive option, especially for commercial customers.

Multiple organizations, including the American Gas Association and America's Natural Gas Alliance, began to pitch natural gas options to automakers as early as 2009. Aside from GM, Chrysler and Ford Motor Co. have also entered the sector.

According to the Journal, Chrysler will build Rams that would be able to get 255 miles on natural gas before transitioning to an eight-gallon gasoline tank for 112 miles. They will be available later this year. Ford, meanwhile, has provided natural gas prep kits for a half-dozen vehicles since 2009.

Richard Kolodziej, the president of Natural Gas Vehicles for America, which advocates for a growing market of vehicles running on natural gas, said Chrysler and GM's new bi-fuel systems were terrific news.

I assume that little by little, all of the automakers are going to get back into the market, Kolodziej said in a phone interview Monday.

About 40 percent of the trash compressor industry employs natural gas-fueled or bi-fuel vehicles. But the consumer market has been slower to catch on. Electric vehicles have been viewed as the main alternative source. And like electric vehicles, natural-gas powered vehicles encounter problems of refueling. According to the U.S. Department of Energy, there are 443 public compressed natural gas fueling stations in the U.S.

But Kolodziej said that following rising gasoline prices and Obama's renewed focus on more alternative options, consumer demand for natural gas vehicles should grow in the near future.

Consumers assume that if it's not available to me, it must not be happening, he said. The only thing they hear about is electric vehicles. But this is happening.