ANGELES NATIONAL FOREST >> For nearly 40 years, reaching Wrightwood or the San Gabriel Mountains ski areas directly from the bedroom communities of the San Gabriel Valley by Highway 39 has been a dead end.

A 1978 mud-and-rock slide took out a 4.4-mile chunk of the mountain highway about 27 miles north of Azusa, leaving a gap between State Route 39 and its more famous cousin, State Route 2, better known as Angeles Crest Highway.

For decades, civic and business leaders called for repairing the broken portion of the state highway bisecting a majestic set of canyons, peaks and rivers enjoyed by more people than any other national forest. And in 2009 the state had answered in the affirmative. But in 2011, just days before construction was to begin, Caltrans announced it abandoned the fix. Instead, the $32 million set aside for Highway 39 went toward repairing a bridge on Highway 1 in Northern California.

Now, five years after the stinging reversal, the cities of Azusa and Glendora, business groups, a local congresswoman and the San Gabriel Valley Council of Governments have convinced Caltrans to consider reopening the road to Highway 2, state and local officials reported.

“We are preparing the engineering design and environmental studies in support of this effort,” said Lauren Wonder, a Caltrans spokeswoman, in an email.

During recent behind-the-scenes meetings initiated by Rep. Grace Napolitano, D-El Monte, Caltrans listened to local leaders as to why the highway should once again connect with State Route 2, officials said. They argued:

• Fires and floods can leave people in Mountain Cove, an Azusa mountain neighborhood, and various mountain camps and campgrounds trapped in the San Gabriel Mountains with no way out. Providing a northerly escape route through Highway 39 to Highway 2 would save lives and also provide quicker fire suppression responses.

• Congestion in the North, West and East forks of the San Gabriel River — popular recreation spots during summer and fall — would be relieved by completing the loop to Highway 2, moving people and traffic through Wrightwood, a quaint mountain town, and connecting to the high-desert communities.

“We believe there is a need to re-examine this issue,” said Azusa City Manager Troy Butzlaff. “We are happy Caltrans is willing to consider going forward.”

One sticking point is the presence of the San Gabriel Mountains bighorn sheep known as Nelson’s bighorn sheep, ovis canadensis nelsoni. In 2011, Caltrans said it was unwilling to rebuild the road because motorists may run into or over the state protected species, particularly the lambs.

Steve Castro, chief executive officer of the Azusa Chamber of Commerce, said Caltrans and the state Department of Fish and Wildlife are tussling over the issue. Caltrans would not agree to build the road without another study that shows the sheep’s location. Previous studies showed the sheep, which numbered 292 in 2006, were mostly at Cucamonga Peak, Mount Baldy, Iron Mountain and Twin Peaks, far from Islip Saddle/Snow Canyon.

Both Castro and Butzlaff will bring their case to the San Gabriel Valley Economic Partnership on Wednesday. “There’s an economic potential. We would be foolish not to consider opening up that road to help businesses,” Castro said.

He said someone from the high desert could enjoy the mountains and have dinner in Azusa. Likewise, San Gabriel Valley residents could cut the drive time to Wrightwood in half. Instead of going east to the 15 Freeway, Highway 138 and Highway 2, or west to La Cañada Flintridge and connecting with Highway 2 for more than 60 miles, the mountains and high desert would be a straight shot of about 32 miles up Highway 39 from the entrance gate north of Azusa.

The San Gabriel Valley Council of Governments, a collaboration of 31 cities, three county supervisors and three water agencies, has written a letter to the U.S. Forest Service, asking to include a completed State Route 39 as part of its management plan for the forest and the 346,177-acre San Gabriel Mountains National Monument. The letter, from council Executive Director Philip Hawkey, says the entire route was included in a 1919 state bond measure. The letter states completion of the 4.4-mile damaged portion would provide better access for recreation, fire suppression and search and rescue teams.

The council governing board will vote on the letter at its meeting 6 p.m. Thursday at 602 E. Huntington Drive, Suite B, Monrovia.