What to Expect: 
This 7 mile section of Stateline Trail #738 is a completely dry hike outside of snowbanks that are present early in the summer; as there is no water source that is easily accessible along the entire route. The trail has some moderately steep sections that are mixed in with some gentle and downhill grades. There isn't a lot of shade so a hot afternoon can be punishing. However the entire length has some outstanding views with some short hikes to higher points to enhance your hike.
There are 9 lakes along this distance; Hoodoo, Hidden, Heart, Pearl, Dalton, Trios (3) and finally Goose Lake at the end. None of these lakes (except Goose) are good candidates for a water stop as they are too far off the stateline (500-800+ ft) so make sure you have enough fluids for the entire distance to or from Goose Lake. If planning on camping along this section before Goose Lake; Hidden, Pearl, Dalton, Upper Trio or Lower Trio Lakes are good candidates. Hidden lake does not have a trail off the stateline and Middle Trio Lake doesn't have fish. The route into the Trio Lakes before Goose Lake is primitive but very doable with a little care. This is my most traveled section of the stateline trail.
Getting There - Hoodoo Pass (Trout Creek Road #250):
At Superior, take Diamond Road east past the Town Pump Gas Station for 6 miles; passing the Bark mill and the Magone Ranches to the end of the pavement where the road changes to Trout Creek Road (#250). Continue up Trout Creek Road (~19 miles), passing the Trout Creek Campground and the Heart Lake trailhead until you top out on Hoodoo Pass on the Idaho/Montana border. The trailhead has no vault toilet so use the one at the Heart Lake trailhead if needed.
Trail #738 Description North to South: From Hoodoo Pass trail #738 takes off directly from the parking lot on top of the pass on an old jeep trail. When I was growing up, a good 4-wheel drive could drive this road all the way to the high point above the basin that sits above Heart Lake. By the time we were taking motorcycles across the route, the Forest Service had blocked access for larger vehicles but motorcycles were still allowed. Currently, there is a substantial push from the motorized community to re-open the stateline trail to motorized vehicles; one argument I have seen is that the closure discriminates against disabled people so the trail should be open so they can enjoy the trail. The trail switchbacks up the hill for 1/2 mile, passing by the trail junction #111 that leads to Hoodoo Lake, before turning into a single track that skirts around the side of the mountain. In a little over a mile of easy walking you will connect back to the ridge top and a nice overlook of Hoodoo Lake.
From there the trail maintains a mostly level grade for a mile before starting to climb at a steady rate and then dropping down a bit as you pass the overlook to Hidden Lake at the 2.75-mile mark. There is no trail down to Hidden Lake except for some sporadic game trails. The trail continues uphill for the next 1/2 mile, passing the intersection with trail #171 from Heart Lake to a high point that looks down into Heart Lake and directly across the valley into Pearl Lake. To me this is one of the best photos along this stretch of the state line trail.
From there the trail drops down the hill, traverses the hillside for a bit before starting a steady climb up to the junction of trail #175 coming from Pearl & Dalton Lakes at the 4.5-mile mark. There are several overlooks down into Heart Lake along this stretch. If water is needed, there is a large snowbank to your left that overlooks Pearl Lake, that usually stays for most of the summer, but I wouldn't count on it late in the summer. This point is also a spot on the stateline that has cell service, not enough for call but simple texts work well.
Continue on the right fork, there is (was) a sign at the junction, down to a spot directly above Dalton Lake. The trail then climbs 300 feet to 7,250 feet before starting the long drop into Goose Lake at 5,780 feet. A good side trip from this point would be to climb up to the dividing ridge between Dalton and the Trios for a great view looking straight down the cliffs into Dalton Lake. There is a trail that takes off down a spur ridge to your right into the Goose Creek drainage. Stay on the main trail.
On the way down to Goose Lake (1/3 mile past the high point) you will pass a nice overlook of the Upper Trio Lake and the primitive trail that leads into the basin above the Trio Lakes. As you near Goose Lake, trail #103 connects from the North Fork of Fish Creek. The state line trail heads down across a grassy slope towards Goose Lake. The trail crosses the outlet and intersects with trail #414 coming up the Goose Creek drainage and the end of this section of the trail.
Getting There - Goose Lake:
I have provided a descriptions to the trailhead on past sections, but in this instance I will just reference the descriptions for Goose Lake. They contain trailhead and trail descriptions from several directions; so see Goose Lake for more detail.
Trail #738 Description South to North:
From Goose Lake head North up the hill from the intersection with trail #103 coming out of the North Fork of Fish Creek. This is a tough climb, 1500 feet in 1.75 miles, from Goose Lake to the High Point above the Trio Lakes. If in the cool morning it is not too bad, but if completing this climb in the afternoon, it is a tough dry go. There are a couple overlooks down into the Trio Lakes to take breaks on the way up and make sure to take a break on the high point (7,250 ft) above the Trio Lakes, you've earned it.
From the high point above the Trio's, the trail heads 300 feet down to the saddle above Dalton Lake and then heads back uphill to over 7,000 ft to the intersection with trail #175 out of Pearl/Dalton Lakes and the snowbank / phone booth high above Pearl Lake. The trail then descends for a mile, passing several overlooks to Heart Lake. About 3.5 miles from Goose Lake, you will make the final climb (0.4 mi) to the high point above Heart Lake. This is a great place for pictures as you are looking directly down to Heart Lake with Pearl Lake hanging across the valley, this is a good picture depending on the time of day and season.
From the high point above Heart Lake the trail descends 1/2 mile (400 ft) to the bench above Hidden Lake, passing trail #171 from Heart Lake along the way. Hidden Lake does not have a trail down but there historically has been good fishing for Brook Trout. The trail climbs briefly and then it is 2.5 miles of either downhill or gentle grades for the rest of the way to the trailhead at Hoodoo Pass, passing trail #111 to Hoodoo Lake a 1/2 mile from the end.
