To get there, take Exit 34 off I-90 and take a left on 468th Ave. Follow the road past the truck stop for about a half-mile until you reach SE Middle Fork Road, also known as Forest Road 56. Turn right and follow the road for a few twists and turns, keeping left when the road splits. After 2.2 miles reach SE Dorothy Lake Road. Take a left, passing the Mailbox Peak Trailhead as you navigate the nearly 11 miles of forest road to the Middle Fork Trailhead. The road is currently in the process of being upgraded and paved and is only open to the public on the weekend. The project is expected to be completed by fall of 2016. The signed trailhead and ample parking area is on the right side of the road, find the trail to the Gateway Bridge at the north end of the lot. View Google Directions >>
The trail begins at the Middle Fork Trailhead, crosses the Gateway Bridge and veers right onto the newly upgraded Pratt Lake Connector Trail. As you leave the bridge, enter the Alpine Lakes Wilderness and follow downstream toward Stegosaurus Butte. From the new trail you can see the old riverside trail below, and after .25 mile stroll you'll reach a bridge spanning Rainy Creek. Cross the bridge and a few dozen feet beyond you'll find the unmarked junction with the Rainy Lake Trail. Head uphill, trading the wide trail for more difficult terrain.
From the main trail, follow the narrow bootpath through lush forest and mossy undergrowth. Rainy Creek is your merry companion for the first portion of your journey, as you climb ever upward toward the lake. The path alternates between very steep inclines and occasional plateaus, while traversing blowdowns and occasional talus fields. While some portions are a bit overgrown, the trail is easy to follow, although mud and slick roots can make your ascent that much more challenging. The occasional views of Mt. Garfield are excellent and the rugged trail lends a pleasant feeling of seclusion. Eventually, after many scrambles over fallen logs and trickling streams, descend down to the shores of Rainy Lake nestled beneath the exposed rock face of Preacher Mountain. An faint trail can be found to the right as you reach the lake, leading to decent campsites and a memorial plaque. Looking for more? There is a scramble route out to Little Rainy Lake that can be used to scramble to the summit of Preacher, but its reportedly very overgrown and something of a struggle to navigate.
This is a difficult hike. Not only is it a lot of elevation, but the route is rough and not for everyone. Be prepared to occasionally use your hands to find some balance and make sure to bring some poles to help keep you steady as you work your way up the steep creek valley. Those willing to brave the trail can look forward to the quiet solace of this pristine alpine lake. Certainly, Rainy Lake would be a great base camp for those that want to summit Preacher or the Pulpit, but it is also a lovely and peaceful destination in itself. Whether you're looking for something a little different or just looking for some solitude, Rainy Lake is a great choice.
There are several areas named "rainy" in the Middle Fork area - Rainy Creek, Rainy Lake, and Rainy Mine. All appear to be named for the above average rainfall the valley receives. Rainy Creek can be found on maps as far back as 1907 and likely lent that name to the lake. For decades, Rainy Lake was a destination for backwoods fisherfolk, who seem to be responsible for cutting the rough path to the shore. Trail Blazers like George Lewis hauled trout fry up this route to stock Rainy Lake (among many other lakes in the area). A plaque honoring Lewis' efforts can be found with a little exploration of the area around the lake. Over the years the trail was maintained mostly by users. It may be that the Forest Service was involved with the trail at some point, but if that ever was the case, the trail is long since abandoned. Today the forest is kept at bay by helpful hikers and anglers who clear a little brush or re-route the trail around major blowdowns. While in recent years the underbrush has gotten the upper hand, there is some talk of reclaiming this trail in the coming years to make the lake a little more accessible.