Nestled in the Alpine Lakes Wilderness of Washington State, near I-90 & Snoqualmie Pass, Pratt Mountain is no stranger to visitors. However, with no clear "trail" to the mountaintop, and with definitive trails going to surrounding lakes and mountains, few people actually attempt to summit Pratt Mountain. To most easily reach the summit of Pratt Mountain, the route changes from a gentle-sloped woodland path to a Class 2 boulder-scramble. The hike is approximately 11-13 miles, roundtrip.
South Slope Boulder-Scramble
The Mountaineers organization named the peak in honor of one of their members, John W. Pratt, who worked at the Seattle Post-Intelligencer (newspaper) for many years.
There are two trailheads from which a person can reach Pratt Mountain.
1) Pratt Lake Trailhead (recommended)
Trailhead Elevation: 1800 Feet
Take I-90 to Exit 47, then head north 0.2 miles to a T-intersection & take a left. The parking lot is around the corner, only a very short distance away. Starting from the Pratt Lake Trailhead is recommended because, although it is a little longer in distance and a little more elevation gain, it offers a gentler-sloped trail than the alternative(s). From the Pratt Lake Trailhead, follow the Pratt Lake Trail (#1007) until it meets the Mount Defiance Trail (#1009) junction.
2) Talapus Lake Trailhead
Trailhead Elevation: 2600 Feet
Take I-90 to Exit 45, then head north along Forest Service Road #9030 until it reaches the Talapus Lake Trailhead. This is an alternative route to the one mentioned above. FS Road #9030 tends to succumb to mudholes and potholes, and the trail tends to be muddy in places, although it is a little less distance and elevation gain than from the Pratt Lake Trailhead. Follow the Talapus Lake Trail until it reaches Pratt Lake Trail (#1007). Take a left onto the Pratt Lake Trail and follow until it meets the Mount Defiance Trail (#1009) junction.
From the junction of Trail #1007 (Pratt Lake Trail) & Trail #1009 (Mount Defiance Trail), follow Trail #1009 (to the left). There are plenty of birds, wildflowers, and huckleberries along this stretch of the route. Eventually, the trail will intercept a boulder field. Rather than following the trail down & around the bottom of the boulder field (towards Mount Defiance), start scrambling the large boulders up & to the left around the hillside. Continuing left, there are several lower boulder fields to cross, each one connected by a very small path in-between. There may or may not be several cairns, left behind by past climbers, leading the way. At about the third lower boulder field, there will be an open connection with the upper boulder field (which covers the upper hillside to the mountaintop). From this point until the summit, you will gain approximately 600 feet elevation over a ¼-mile. At the mountaintop there is a central-located clearing between the trees; head to that spot. The clearing marks the “false summit”, which has scenic views of nearby lakes and peaks, as well as Mount Rainier. From the “false summit”, head left along a very short trail through the trees. The true summit is a hill of boulders, approximately 20-30 feet higher than the “false summit”, located on the other side of those trees.
A Northwest Forest Pass (i.e. parking pass) is required for parking at either trailhead.
Each hiker/hiking group must sign-in at (or shortly after) the trailhead & obtain a free hiking/wilderness permit, as well.
NOTE: There are several other possible variations of traversing Pratt Mountain, but each variation would require some bushwhacking & keen mountaineering skills, and none of which are clearly accessible or marked.