If you're up for some gravel/dirt/snow driving, then this trail offers an excellent opportunity for that in addition to a great prize at the end.
You start out from hwy706 near Alder Lake. Head east about 10-15 miles and watch for the entrance for Forest Road 84 on the right. It will be a long perfectly straight road for about a mile, then you follow the signs to FR8440/High Rock.
It's about 10 miles of gravel to the top. Once there, you'll find a trailhead for the High Rock Lookout trail. It's a 1.6mile hike with a reasonable elevation change to get up to this:
There are many other distractions along the way, such as Cora Lake, which you can also easily find from FR84. Cora Lake is the spot of blue water you see directly below you when you look straight down from the lookout. The hike up to Cora Lake is much more thrilling in that there are stream crossings and such. Once there, you'll be greeted by a pristine mountain lake that is definitely worth the hike.
Wilderness rules apply, so be careful for the wildlife!
FR84 can be rough in places so watch out for punctures and always carry a spare when you go offroading in the wilderness.
If you get done with this early, the road to Paradise, WA (the village at the base of Mt Rainier) is just a few more miles up hwy706 and is worth every drop of gasoline it takes to get there.
I was last there in 1998 and it was in the July following the winter where the all time world record snowfall in one season had occurred over at Paradise on Mt Rainier, so there was a lot of snow around and getting to the High Rock Trailhead involved some serious snowslush-bogging. It was also quite brisk out that day, but it was still a pleasure to be out there.
More info on High Rock is at http://www.forestlookout.com/highrock/highrock.html