i have been taking the dog for little walks in Hahamongna Watershed Park for a while, and we also hike Cherry Canyon fairly often. I was pretty excited to try this trail when it reopened and link the two.
Flint Canyon Trail definitely has some good points. The restoration has made the trail safe and easy, and it's a good length -- from where we parked in the frisbee golf parking lot at Hahamongna, it's a little over 5 miles if you do the full round trip (the actual Flint Canyon Trail portion is shorter). The signage is excellent. As the other review noted, it's shady for much of the length and the Flint Canyon stream bottom is beautiful. There's a little stepping-stone crossing that is charming and gives your pooch if you bring him a chance to do a little wading. We saw lizards, birds, butterflies, and one coyote going about his business. We also met a friendly, curious horse in a paddock alongside the trail.
Unfortunately, almost the entire trail is blighted by chainlink fencing, deafening freeway noise, or urban development. I don't hike to look at suburban backyards, walk on residential streets, or explore the undersides of freeways. It is SCARY under the 210, there's a long dark stretch with enclosed concrete bays, so you can't see whether anyone's inside until you are right next to them. The other reviewer wasn't kidding!
Basically, the trail restoration was lovingly done (although the budget clearly didn't stretch to wood fencing instead of very ugly caged-in chain link) and the trail is useful for equestrians trying to get from the staging area at Hahamongna to the trails at Cherry Canyon. It's probably also great for trail runners because the terrain is well-maintained and it's not crowded AT ALL (I only enountered one other hiker on a sunny Sunday afternoon). But the potential for hikers is largely ruined by San Gabriel Valley suburban sprawl and car culture. I can't give it less than 3 stars because the trail volunteers have really given it some loving attention -- but I can't give it more than 3 because factors beyond their control make this a disappointing hike. read more