This drive is a relaxing alternative to the freeway between Coeur d'Alene and the summit of Fourth of July Pass, so named after Mullan's summit encampment on July 4, 1861.
The terminal points are Interstate 90, Exits 17 and 28, with entrances and exits from any direction. If you want to drive this route from east to west, just reverse the description below.
To start, leave I-90 at Exit 17. It near the top of a hill above Coeur d'Alene Lake about two miles southeast of that city. The exit is signed as Mullan Trail, so it is hard to miss. (If you take the Yellowstone Trail exit by accident, you can join this route by following Sunnyside Road.)
Mile 0: Follow present Mullan Trail Road as it winds its way over and through the hills abutting the lake. The modern road follows the original very closely.
Mile 1.7: Turn left (north) on Sunnyside Road. Sunnyside Road follows the historic Yellowstone Trail, which in turn followed the original Mullan Road here. It also named Yellowstone Trail on many maps.
Mile 4.3: After crossing Blue Creek, the historic Mullan road climbs the hills to the east. Stay on
Sunnyside Road/Yellowstone Trail as it bends south around the Blue Creek Bay.
Mile 4.6: Blue Creek Trail and Recreation Area has parking, a pit toilet, and several hiking options managed by the BLM. More
Mile 5.5: Now named Yellowstone Trail, the road hangs on to a steep cliff directly above I-90. There is no guardrail, so try to keep your eyes on the correct road instead of the spectacular views of Lake Coeur d'Alene and Mineral Ridge on the opposite side of the lake. Given the work to cut this road through the rock cliff, you can see why Mullan went up and over the ridge.
Mile 6.6: Arrive at the junction of Idaho State Highway 97 and I-90, Exit 22.
Exit 22. Continue east as the road changes its name to Frontage Road.
Mile 7.4: Turn left (NE) onto Wolf Lodge Creek Road.
Mile 8.2: The original Mullan Road joins your present route and now follows it closely.
Mile 9.2: Continue to the right (SE) on Alder Creek Road, a well-maintained gravel road. Alder Creek Road has several large cuts and fills made with machinery and time that Captain Mullan did not have available. Mullan needed to climb over hills and ridges in a more direct line. The present route is an enjoyable drive up to the summit and stays completely out of the steep, winding canyon followed by the Interstate to the south.
Mile 14.8: Alder Creek Road rounds a sharp bend with a massive road cut from the rock mountain.
Mile 15: Fourth of July Pass summit and interchange. From here, you can return to the freeway, picnic near a Mullan statue, or hike an old segment of the road on the interpretive trail maintained by the Forest Service. You can also continue down the east side of the pass following the Yellowstone Trail, a gravel road.