Trail 506
The Salmo Basin
This trail lies partly in the Priest Lake Ranger District and partly in the Sullivan Lake Ranger District. This trail is easily accessed from the Salmo Pass Trailhead in the Sullivan Lake Ranger District. Since the trail undergoes dramatic elevation changes along its route, the best way to enjoy the trail is to hike the Salmo Loop (Salmo Pass Trailhead - Trail 506 - Trail 512 - Trail 535 - Salmo Pass Trailhead).
There are two straightforward ways to reach the Salmo Pass Trailhead from Priest River, Idaho.

One:
Take Highway 57 north out of Priest River and follow it until it becomes US Forest Service Road 302. Continue on Road 302. Follow the signs to Metalline Falls when you reach Granite Pass - that way you will be sure to stay on Road 302. Once you leave the Priest Lake Ranger District and enter the Sullivan Lake Ranger District, the road will be marked as Road 22 (not Road 302). Minor detail! Folow it until it dead ends into Road 2220. Turn right and follow Road 2220 until you reach the Salmo Pass Trailhead - actually the road ends at the trailhead, so you can't miss the trailhead.

Two:
Take Highway 2 out of Priest River towards Oldtown, Idaho. Just before crossing the bridge over the Pend Oreille River in Oldtown, turn right onto LeClerc Road and follow it to Road 2220 in the Sullivan Lake Ranger District. Turn right onto Road 2220 and follow it to the Salmo Pass Trailhead.
From the Salmo Pass Trailhead, Trail 506 descends 1800 feet to the Salmo River. Take time to enjoy the river valley before you begin the hike up the mountain to Trail 512 and Little Snowy Top.
On your way back from the Salmo Pass Trailhead, turn right at the first opportunity. This will put you on Road 270. Follow the road to the top of Salmo Mountain. Park your vehicle and climb the steps of the Salmo Lookout Tower to the viewing platform. The views are breathtaking. Try to arrive in time to enjoy the sunset.

The above photo shows Salmo Mountain and the Lookout as viewed from Road 270.
Salmo Mountain Lookout
(click on the picture to see some views from the Lookout's Viewing Platform)