Nestled between Mount Washington to the east and McClellan Butte to the west is a ridge that splits the Hall and Change Creeks. If you're driving I-90 and take a look to the south between the two Exit 38s, you will see the ridge I'm referring to. It juts out all the way to the Iron Horse Trail, and meets up with Mount Washington to the south. This past weekend I went exploring this area and was pleasantly surprised at what I found. A short trail (about 1.5 miles) with about 1900 feet of total elevation gain made for some wonderful hiking and better views.
Parking for this area is between the two Exit 38s off I-90. If you are coming from the west, go right off the exit, go past the Twin Falls trailhead, and about a quarter mile down the road you'll see an old road-turned-into-parking (can't miss it). Park there, and at the point where the road crosses Change Creek, you'll find an unmarked trail on the west side.
This trail takes you up to the Iron Horse trail, and you are likely to find plenty of rock climbers here - this is arguably the most popular area west of Snoqualmie Pass for rock climbing. Once you get the Iron Horse trail (about 300 feet of elevation gain), go east across the Change Creek bridge, taking time to enjoy the wonderful views of Change Creek. Also, take a peek to that ridge just east of the bridge, that's where you'll be heading :)
To the east the Iron Horse trail next crosses Hall Creek, and there's a large bridge for that. Just before it, on a smaller bridge, you'll see an unmarked trail right next to the fence. Take it, and it will switchback up about 500 feet to the first viewpoint, an awesome view of Hall Creek below. Continue up the trail, a steep climb for the next half mile or so. At about .8 mile past the first viewpoint, you'll come to an area where you are on a ridge that splits both Change and Hall Creek - you'll know it when you come to it. Remember this spot and continue up the trail another .2 miles. There will be a turnoff and a sign labeled "Hall View" or something similar. Take that trail up a short ways, and you'll be rewarded with an awesome viewpoint of Change and Hall creeks. Arguably one of the best viewpoints (Snoqualmie Valley, Middle Fork, Mailbox Peak, Mount Si) that's not a mountaintop in the valley.
Back at the main trail, it continues on and meets up with an old logging road that will eventually wind around Change Creek and take you to the top of Mount Washington. On this day, I headed back down to the ridge I referred to earlier. Instead of taking the trail down, I wormed my way along the rocks on the ridge for .1 miles and was treated with making it to the ledge that juts out to the Iron Horse Trail, which at this point was about 1200 feet below. Again, awesome views of the valley.
A word of warning, this last trek is not suitable for small children, and I would be wary of the trail above the first viewpoint with small kids. Some steep dropoffs off a narrow trail. Not a family friendly hike.