Mount Zircon in Rumford is a gem! The 5.5 mile round trip is a low-key hike or a perfect place to try mountain running.
The trailhead is easy to find off South Rumford Road. Although you are welcome to park below the gate, the water department owns a lot just before the trailhead with much easier access.
The first couple miles are a climb up a gated Jeep road, both sides of which are posted by the Poland Spring company and other landowners, but folks are welcome on the road itself. The road is steep in places, but the footing is pretty clean because the road is still maintained for vehicle access by the landowners. It's a great place to start exploring mountain running because you can start to challenge yourself with a sustained climb without managing technical terrain. It allows you to focus on your body signals and start learning how to manage pitches and intervals without other complications.
Your climb up the road leads past a spring house and the foundations of an old hotel. Graciously, the landowners have left the shutters open on one window of the spring house so that runners and hikers can see down into the old Moontide Spring company's spring--bring a flashlight or a headlamp so you can get a good look. There is even a PVC outlet across the road from which you can get water, but it is untreated to act with appropriate cautions.
You'll continue up the road a little farther to the true trailhead for Mt. Zircon. Here, the half-mile trail becomes narrow, steep and starts to feature the rocks and roots more typical to trail running in Maine. If you're running, you're likely to discover that your intervals become shorter as the trail is more challenging here. No worries! Mountain running implies walking or power-hiking intervals. It's natural to shift strategies and slow your pace as the trail becomes more challenging.
After a quick scramble up some ledges, you reach the open summit of Mt Zircon. Although there was once a fire tower at the summit, the Forest Service has pulled it down in the interest of safety. But even without the tower, you have a 360 degree view from a series of viewpoints. There's plenty of elbow room at the top, which makes it easy to maintain social distance from other parties.
I typically budget the same amount of time to descend the singletrack as to climb it, as technical descents can be tricky for my short legs: slow is safe and safe is fast. Once you make it back down to the Jeep road, the final two miles back to the gate are a much quicker run.
You'll definitely feel it in the morning, especially if you are new to mountain running. You've likely taken on a longer sustained climb than you're used to running, and don't underestimate how a downhill run can make your quads burn. Take the next day for yoga, cross-training or a super-easy recovery run. Your body deserves it!
Bonus Adventure: for those of you who are tempted to keep exploring, the Jeep road you climb to the singletrack is called Zircon Road. The climb continues for another half-mile or so until descending for two miles, often sharply, to a side road through a small neighborhood in East Milton. From the crest of the hill to East Milton, the road condition deteriorates quickly to an ATV trail, which makes for a fun technical run. Don't forget to look up from your footing, as a couple of the steepest pitches also offer lovely views. As you approach the bottom, the road quality improves to allow logging equipment through. Running Zircon Road from Rumford to East Milton and back is a little under ten miles.