Fishlake National Forest has paved the way for a controversial natural gas line to be routed through the Scipio Pass corridor.

J. Kent Taylor, Fishlake National Forest supervisor, announced the decision to allow the pipelines to use the existing utility corridor in the national forest. The action follows on the heels of a decision by Wasatch-Cache National Forest officials to approve construction of two parallel trenches along a route through the Salt Lake Valley.Pipelines are expected to be built from Opal, Wyo., to Southern California by the Kern River Gas Transmission Co. and the WyCal Gas Co. Kern River has announced it will soon begin construction on the southern end of the line.

The Forest Service decisions will have an impact in south-central Utah. Officialsin three counties hope to get natural gas, either from a commercial firm or through municipal systems for the convenience of the area's residents and to enhance industrial development.

Although Mountain Fuel Supply Co. hasn't asked for franchises in Beaver, Juab or Millard counties, the groundwork is being laid through meetings with city councils, mayors and county commissioners in two of the counties.

The company's officials have stated they will seek franchises if they can tap gas lines coming through the area. The corridor for the WyCal and Kern River lines goes through all three counties.

The Central Utah Gas Co. of Nephi, which has yet to deliver any natural gas, has secured non-exclusive franchises in Delta and Millard County. This wouldn't bind commissioners or city councils from letting another company provide the service, however.

Juab County officials appear to be leaning toward a municipal gas system.

It is not anticipated that the Utah Public Service Commission would authorize both companies to supply natural gas to the area.

Taylor's decision may be implemented by late November. It is subject to appeal through the Intermountain Regional Forester. Copies of the decision and the Forest EIS and Supplement are available for public review at the supervisor's office in Richfield.

Mountain Fuel, which installed lines and began service in Sanpete, Sevier, Iron and Washington counties within the last three years, is expected to charge about the same price in Millard and Beaver counties as in the other counties which now have the service. About 20,000 consumers in these counties are paying 22 percent more for the service than those on the Wasatch Front.

Consumers in Millard, Beaver and Juab counties could be getting natural gas delivery for the first time by late 1991 or early 1992.