A Ramble on Chino Hills Trails Near Tres Hermanos

As the future of the Tres Hermanos Ranch in Tonner Canyon becomes increasingly more debated, given the likelihood of its sale by the City of Industry in upcoming months and then the move toward rezoning for residential and commercial development is made, a hike on a couple of City of Chino Hills recreational trails seemed in order.

Looking southwest from the Sunset Park (Grand-to-Sunset) Trail at the Tres Hermanos property and south towards the end of Tonner Canyon at Brea.  Click on any image to see the set in expanded views in a new window.

Taking place on a relatively mild late Saturday afternoon, the walk took in about five miles of the Sunset Park (called Grand-to-Sunset on Google Maps) and Grand Avenue Park (known to Google Maps as the Tonner Ridge) trails in the northwestern corner of the city.  Both of these trails skirt the eastern edge of Tres Hermanos on both sides of Grand Avenue.

These trails give excellent views of the ranch that are not obtainable anywhere else (well, short of trespassing, that is), as well as nice surveys of other areas from heights that give 360-degree views.

This view looks northwest from near Sunset Park.  At the lower right to center is a natural drainage to what appears to have been a reservoir with a small rock dam at the center.  From the Sunset Park (Grand-to-Sunset) Trail.

In some cases, you can find spots in which the right angles exclude any sign of development and take in undeveloped areas.  Of course, if Tres Hermanos is developed, many of those vistas will be gone.

In any case, the Sunset Park trail connects the park of that name at the top of the neighborhood that is near the intersections of the former Gordon and Laband ranches to Grand Avenue Park.

The headquarters of the Tres Hermanos Ranch.  The small hill at the left once contained the ranch house built in the 1910s.  The current lessee uses the site as their headquarters.  In the background are homes in Diamond Bar. Taken from the Sunset Park (Grand-to-Sunset) Trail.

The total length of trail one-way might not be more than a mile or a mile-and-a-half, but there is one section that is a very, very steep ascent and descent of probably 30 degrees or so and there are other fairly steep climbs, so unsuspecting hikers should beware.

From this trail, excellent views can be had of the old headquarters for the Tres Hermanos ranch, including the low tree-topped hill where, until a few years ago, the ranch house built in the 1910s by the "three brothers": Harry Chandler, publisher of the Los Angeles Times; Rancho La Puente scion, two-term Los Angeles County Sheriff and Puente Oil Company founder William R. Rowland; and oil magante William B. Scott.

A close-up of part of the Arnold Reservoir on Tres Hermanos Ranch taken from the Sunset Park (Grand-to-Sunset) Trail.

Today, the lessee of the ranch has trailers, smaller structures, corrals and other elements in use for running cattle at this location.  Just a bit to the north is the reservoir, now known as Arnold Reservoir.

Other locations on the trail show the ranch heading southward to lower Tonner Canyon, where there is the Boy Scouts Reservation and more property owned by the City of Industry and subject to sale, which leads to an opening out at Tonner Canyon Road and the 57 Freeway.

This is the northeastern corner of Tres Hermanos Ranch with some corrals and other infrastructure for cattle ranching at the center left.  Taken from the Grand Avenue Park (Tonner Ridge) Trail.

Again, those sections of Tres Hermanos south of Grand Avenue and visible from the Sunset Park Trail are within Chino Hills and are subject to the provisions of Measure U, requiring voter approval for any zoning changes.

Chino Hills residents concerned about what could happen to the ranch might benefit from making even the very short climb from the park to the first two vista points, before the steep trail section, and sit on one of the two benches and take in the amazing views.  This little excursion of a few minutes could be a deciding factor on zoning change vote!

The Grand Avenue Park (Tonner Ridge) Trail looking north toward Mount San Antonio (Baldy) and Ontario and Curamonga peaks.

The Grand Avenue Park (Tonner Ridge) Trail heads north from the park and climbs with moderate steepness up to some hills that flank east side of the northern reaches of Tres Hermanos.

From areas along this section of trail, there can be viewed other corrals, watering troughs and other infrastructure for the cattle raised on the ranch.  Tonner Canyon Road ascends at the northeast corner of the ranch and terminates at a locked gate along Chino Hills Parkway.

Looking towards the south with Carbon Canyon and the Santa Ana Mountains in the distance along the Grand Avenue Park (Tonner Ridge) Trail.

The trail then descends to Chino Hills Parkway after moving around a section of housing that is the farthest northern part of Laband Village. Once reaching Chino Hills Parkway, there are more trails across the road that make up the La Sierra Trail Loop system.

As noted before, there are also excellent views to be had of points north and east towards the San Gabriel Mountains and the trio peaks of Baldy, Ontario and Cucamonga, as well as the rolling hills and settled areas of Chino Hills and beyond to vast areas of the Inland Empire.

One of the many panoramic views of Chino Hills from the Grand Avenue Park (Tonner Ridge) Trail.

For an early September day, it was actually fairly clear, though obviously the clearest views will be in the winter and spring, especially if we get the kind of rain some project for the El Niño winter season.

Tres Hermanos represents one of the last remaining stretches of undeveloped land in our region.  For that reason, investors and developers are hungrily eyeing the property and conservationists and others are hoping to preserve what they can.

A view of a section of Tres Hermanos Ranch from the Grand Avenue Park (Tonner Ridge) Trail looking southwest.

Given the fact that the area of the ranch north of Grand Avenue lies within Diamond Bar and will likely be rubber stamped for a zoning change by the city's government, but also because it does have an outlet to Chino Hills Parkway and the 60 Freeway that provides some accessibility, this appears to be the portion of Tres Hermanos best suited for development.

It's the area south, bordering the Boy Scout Reservation and Chino Hills State Park (which, theoretically, could be expanded into this section), and containing what could be, in the form of the old ranch headquarters, a designated historic site, that stands the best chance of preservation or, at least, significant mitigation.

A beautiful spreading oak along the Grand Avenue Park (Tonner Ridge) Trail.

Again, as part of Chino Hills, the southern section of Tres Hermanos falls within the purview of Measure U, requiring voter approval for a zoning change.  Water scarcity, wildfire risk, inadequate traffic accessibility to the site (watch for an effort to extend Eucalyptus Avenue, though, if a project is developed), and other issues are going to be significant ones.

The Arnold Reservoir and adjacent ranch headquarters could be a visitor's center and parking area for an expanded Chino Hills State Park or a separate regional park with trails winding through the canyon and ranch.  But, this would require lots of planning and money and from where would the resources for both come?

Someone obviously thought it would be providential to repurpose these old fence posts from what was likely the Laband Ranch along the Grand Avenue Park (Tonner Ridge) Trail.  It will take some form of intervention to preserve signficant portions of Tres Hermanos Ranch from major development.

Of course, if there is a Measure U election, it would be expected that the property's new owners would engage in a well-financed multimedia campaign to wow Chino Hills voters will all kinds of promises of mitigation efforts in the form of money for schools, parks and other community amenities, revenue brought to the city by development and the tax base provided by thousands of new residents, and other lavish benefits.

Tres Hermanos is truly a final frontier--of the last remaining undeveloped area of size in our region and of the final major pitched battle of contending forces among developers and preservationists.  Who knows when or in what form the development proposals will arrive and who knows what the response will be?  In any case, it will be very interesting to see what unfolds in coming years.

This is a water trough from what was probably the Laband Ranch along the Grand Avenue Park (Tonner Ridge) Trail.