The trailhead lies on US Route 26 and features parking for 51 vehicles, although parking can be had along the heavily trafficked road. Parking is free from October 2 through May 14, but requires a Forest Pass or $5.00 day use fee during the high season, May 15 - October 1. The trailhead features restrooms and an information kiosk. Remember that doggos must be leashed at all times on this trail, and be sure to bring water to share, and clean-up bags.
Mirror Lake Trail includes 10 footbridges over creeks and wet, muddy areas, including one that is simply a large log with a handrail. Exciting and fun for children, please be very careful with your pup while crossing. The main trail travels 4.4 miles and over 600 feet up to the lake, around it and then descends back to the trailhead. This is a very easy walk despite continuous uphill hiking on the way in.
If you and Fido want to extend your hike another 1.8 miles, and afford yourselves some even more puptacular views, keep going north at the lake instead of around it to catch the trail that climbs up the slope of the Tom, Dick and Harry to its ridge and summit. This is a fairly easy climb at first, but at the top you will have accomplished about 1500 feet elevation change, the last 200 yards being rough, rugged rock-climbing. Rewarded by views of Mount St. Helens, a different perspective on Mount Hood, and a distant Mount Rainier, the extra climb is worth the effort. You may even spy peregrine falcons flying overhead.
After returning from the Tom, Dick and Harry ridge, continue around the lake to the part of the trail that leads back to your car. This is a truly woofderful hike, evidenced by its pupularity and thick traffic! If you're in the area, try it out!