Here is the trail description from NW Hiker.
Length: 6.4 mile with loop
Elevation Change: 1600 gain
Season: Late Spring thru late summer
Permit: NW Forest Pass Required
Features: This hike begins at the highway 26 Mirror Lake trail head. Most of the hike wanders through dense forest. There are only a couple areas where you can view the surrounding mountains and valleys until you reach the lake itself. Just before Mirror Lake you intersect the loop trail that goes around Mirror Lake. Keep to the right and you will pass by the north side of the lake. Once again, you must bear right to avoid following the loop trail. The trail to the top of Tom Dick and Harry Mtn climbs gently over the next mile with exceptional vistas of Mt Hood and the surrounding valleys. When you reach the ridge top, a large pile of rocks will greet you. The trail turns sharply to the left and wanders through a scrub forest. About a third of a mile before the summit, the trail begins to climb steeply over rocky terrain. Upon reaching the top, you are treated to one of the best vistas in the entire Mt Hood National Forest. During season the flowers are abundant. This hike is one of the very best and of course quite popular.
More info can be found at: http://www.portlandhikersfieldguide.org/wiki/Tom_Dick_and_Harry_Mountain_Hike
Round trip mileage is about 110 miles from the carpool site.
Northwest Forest Pass is required.
I understand and agree the hike leader is a volunteer willing to have others join them, and I will follow their requests and direction in their role of hike organizer/leader. I understand and agree that sometimes hike leaders make mistakes, sometimes fellow hikers make mistakes, sometimes I make mistakes, and/or sometimes things happen and luck runs out. The hike leader and fellow hikers will do their best but are not responsible for my personal safety, valuables, or fun for the day…these are fully my personal responsibility.