Tri-Valley residents may one day be able to travel on foot or bike through Niles Canyon on a nearly six-mile proposed trail that would link the eastern end of Fremont and the unincorporated community of Sunol — which Alameda County officials also said would ”preserve the historic water and rail infrastructure within Niles Canyon.”
In a public update on the project last month, officials said, “Improving access in the canyon is a gateway to open space for Alameda County residents.”
Rick Yeung of the Alameda County Public Works Agency, which has also partnered with the Public Utilities Commission and the East Bay Regional Park District for the project, told the Weekly that development of the 5.8-mile bicycle and pedestrian connection will use a combination of new trail sections, portions of the former Sunol Aqueduct, and existing railways for a route running from the Niles District in Fremont to Sunol.
“Much of Phase 1 from Niles to Palomares Road uses existing roadways for the trail,” Yeung said. “Phase 2, which is from Palomares Road to the Niles Canyon Railway Yard near Brightside, re-purposes the aqueduct as a trail for about 25% of the route. About 70% of Phase 3 from the Niles Canyon Railway Yard to Sunol requires the construction of new trail.”
Yeung said planners may need to secure an easement to cross private property, “which would require payment for the full market value of the land,” though a private landowner is not required to grant an easement.
The area in question is small, but Yeung said, “If this becomes an issue, the project will need to adjust the trail’s location, which may increase construction cost and complexity.”
With some parts of the proposed trail adjacent to the Niles Canyon Railway or Highway 84, or near steep slopes, features like retaining walls and a pedestrian bridge at Palomares Road will need to be built. Parts of the aqueduct will also get a layer of asphalt on the top surface, as well as a second concrete exterior wall and handrail for pedestrians.
Visitor parking at the existing Niles Plaza parking facility and the Alameda Creek Staging Area would be linked to the trail, along with a new parking area at Palomares Road and the future EBRPD Tyler Staging Area.
Because of “a significant increase in people experiencing homelessness within Niles Canyon over the last decade,” Yeung said “unfortunately, this has led to illicit activity including the disposal of waste and toxic substances such as spray paint,” and will require cleaning the canyon.
However, Yeung said officials believe the trail’s development “will create ‘eyes on the canyon’ that will help to prevent encampments and illegal waste disposal.”
“It is difficult to predict the number of trail users,” Yeung said. “However, when looking at other regional trails in the Bay Area, we anticipate a peak of about 400 people on a nice weekend day.”
According to Yeung, the entire trail “exceeds $100 million to complete,” with the first phase at a total development cost of about $29 million. The Alameda County Transportation Commission, Alameda County, Metropolitan Transportation Commission, and city of Fremont have all provided funding for the project.
A source of construction funds has not been identified yet, but Yeung said “a project of this scale will likely receive a combination of funds from local, state, and federal sources.”
The county is currently developing an environmental impact report; a scope session will be held in the early summer and open for public comment. To learn more about the project, visit www.nilescanyontrail.org.



