Middle Fork of the Boise River, Rock Creek Canyon and Timpa Lake

The trail up Rock Creek to Timpa Lake is accessed from the Middle Fork of the Boise River Trail 3.6 miles up the canyon from  Mattingly Junction.  Check out that adventure for an overview of the M.F. Boise canyon or the Atlanta overview for more general info about the greater region.

Rock Creek Canyon and Timpa Lake

The canyon between Mattingly Junction and Rock Creek traverses through sparse forest on a series of connected alluvial fans that have accumulated on the valley floor beneath Peak 9,266. Depending on how far you have traveled, hiking this section can feel a bit like riding a slow-moving conveyor belt through the somewhat monotonous canyon landscape.

The trail up Rock Creek to Timpa Lake feels like a bit of an anomaly. The astounding 45 switchbacks probably required some of the most extensive trailwork in the Sawtooths, yet they lead to one of the least impressive lakes in the range. Timpa Lake sits at the bottom of a narrow cleft. Surrounded by lush grass and fed by numerous springs, it is hard to get within 10 feet of the shore without getting your feet wet.

From the map it might seem that the Rock Creek Trail provides the best access into the Surprise and Confusion Lakes Basin. The scramble from Timpa, however, is a bit of a thrash through dense forest and underbrush. It is far easier to climb the Middle Fork Trail to the Ingleborg Divide and then traverse off-trail into Low Pass Lake.

One of the things that Timpa does have going for it is the solitude. Dead-end trails tend to get less use, and if the overgrown feel of the trail is in any indication, the canyon probably sees only a handful of visitors each season. The other attraction is the stunning hike along the creek upstream of Point 8,920. With its four waterfalls, this section is in the running for one of the most beautiful creek-side trails in the wilderness. And the views across the valley to the Mattingly Peak massif are not too shabby either. 

Two creek crossings have the potential to derail access to Rock Creek. The first, across the Middle Fork, is probably manageable at high water. The second, across Rock Creek, requires some striding leaps between large boulders at low water and has the potential to be very intimidating at higher flows.

Off-Trail Hiking

If you are going to make the hump up to Timpa Lake, it seems worthwhile to climb Peak 9,737. The west ridge is a straightforward scramble and can be looped south to Point 9,242. This perch in the center of the Middle Fork of the Boise River drainage offers an outstanding perspective of the canyon as it splits around the Billy Creek buttress. It also looks directly into the secluded north side of the Mattingly Peak Massif.

Wilderness Regulations

Most of the trail lies within the Sawtooth Wilderness. Please observe the following  regulations:
• Mountain bikes are not allowed past the wilderness boundary.
• Self administered wilderness permits are required and available at the trailhead.
• Dogs must be on a leash between July 1 and Labor Day.
• Camp 100 feet from trails, lakes and streams.
• Pack out all garbage.
• Human waste should be buried and well disguised in a cat hole 6 to 8 inches deep.  Pack out all toilet paper.
• Campfires allowed ONLY in a backcountry pan or fire blanket.
• Campfires are NOT allowed at some lakes and in some drainages in the Sawtooths. Please review the campfire restrictions at individual trailheads.
• Permits required for all stock use in the wilderness. No grazing allowed in the Salmon River watershed (this includes the Alpine Lake drainage).
• No equine stock at Edith Lake. ALL stock prohibited in the Goat Creek and Alpine Creek (Alturas Lake) drainages.