Coming from Montreal this was a perfect little 1 day roadtrip/hike, took the back roads to get there (Saint-Chrysostome, same time as highway) went through a small borders office (that closes a 4pm)
there's a nice park at the end of Chazy lake, keep an eye out for Lowenburg road to get to the Lyon mountain parking lot, the sign is hidden behind trees.
the hike was great! Starts ordinary and gets more and more technical. Crossed a couple of small creeks, lot's of fallen trees, moss, big boulders etc...
took us 2h to get to the top and 1h15 to get back down, it was a 13km (not 10km as this page says)
The top is amazing, the view is incredible!
That shaky/rattling fire tower is a bit sketchy at first but well worth it, watch your head when you get to the top...

Challenging hike but well worth it. Being a novice hiker I thought I may have picked the wrong trail but we got through it. A moderate challenge but I wouldn't call it difficult. There is one section near the top that has a fairly steep ascent with large rocks on the path that were wet and slick at the time. Other than that it wasn't too bad. It felt very rewarding at the end of the day.

Did this hike early May and learned how the temperature can drop 10 degrees every 1000 feet up. It was snowing at the top and the trail was all snow the last 0.5 miles up. The fire tower was frosty and unfortunately the view was poor because a cloud was sitting right on top of us. Finding the trail head was not too difficult. You go on a dirt road to get to it and there was plenty of parking especially since no one hikes mountains early May! I would like to try this one again in different weather conditions. Overall not hard and the trail was not near as rocky as the ones I have done in the past.

My first hike, and it was a great experience! The way to the top wasn't excessively difficult, but the views were astonishing. We reached the top to find ourselves engulfed in a cloud, and as it passed we eventually saw the beautiful views open up. I would definitely recommend this trail, it has well placed checkpoints and a very clear path.

Nice trail.... Hard for people with no hiking experience like us. We got sun, rain and thunderstorms.... It was good

My hiking partner and I took the switchback trail and found it really nice and relatively easy. Views are gorgeous on the top. I wouldn't claim the switchback trail as hard, but moderate. Only wish there was a sign and the parking lot indicating which way the trail is, even though it's not too hard to figure out.

Great new trail and gorgeous views at the top. Doable for any level of hiker. It was a little muddy in parts, but not a problem. Hiked early yesterday and only encountered a few folks. Met more families on the way down.

Always a beautiful hike and great for kids and first timers. There is a long switch back trail or the old trail that is much shorter but lots of round stones to hurt your ankles! The switchback is my choice. I did once run face to face with a black bear but it thankfully ran off. The view at the top of this mountain is truly breathtaking!

It was a challenging climb, would suggest to moderate climbers. I did the switchback which is still a bit challenging. Love the view of the Chazy lake at the top!