Backpack to Marten and Kelly Lakes

Rate this Adventure Idaho Flat Creek Rd Trailhead

Added by Garren Moore

The hike to Marten Lake is a one day, 10 miles out-and-back hike. Find an amazing campsite at Marten, Kelly, or Elizabeth lakes (one or all three!).

The Sawtooth mountain range consists of hundreds, maybe thousands, of small, crystal clear lakes. Because of the sheer number of lakes, there are many destinations where the foot traffic is considerably low. Most weekend packers will stick to the familiar: they find themselves hiking to Sawtooth lake, while beautiful, might be confused with an outdoor mall.

Enter Kelly and Marten lakes, one of the many perfect weekend-trip lakes in the Sawtooth range but not nearly as trafficked (as of the writing of this post!) as Redfish, Stanley, or Sawtooth lake. To reach Marten lake on a weekend or day-hike starts at a turnoff from highway 21, Flat Creek Rd. While the first quarter mile or so of Flat Creek Rd accessible, it really takes a small SUV/wagon to go any further. The road has large divots and consists of large sized granite rocks making it unforgiving to the modern sedan (sorry Prius). Once making it to the trailhead (elev. 6700), which is marked by the obvious trailhead and parking lot (pictured), be sure to sign in for your safety and the law. No worries, the trail is very well marked throughout this entire hike.

The trek to Marten lake is about 5 miles and climbs to 7615 ft. The landscape is mostly flat and barren with charred trees for the first half of this part of the hike, be sure to stop, refill your water, and rest once you hear the creek's waters rushing. After resting at the creek is when the beautiful forest fills out and start to gain elevation.

You'll come to a crosspath when you're just about to arrive to Marten. Go straight until your feet get wet (and you're in Marten) or turn left (south) to go to Kelly Lake (of which the majority of the lake pictures are included in this post). Kelly lake is another mile and sits at about 7900 ft. It is very similar to Marten lake, so if you find beauty in Marten only the extra curious should venture on. While possible, I would not recommend going to Kelly on just a day hike as that can stretch the beginning hiker a little too far.

Pack List


  • Daypack (18-24L)
  • Light jacket
  • Trail shoes/hiking boots
  • Water, filtration system to refill (from the trailhead to about mile 3, there is no accessible water - remember that on the way down)
  • Camera


  • Weekend pack (40-55L)
  • Hiking boots
  • Tent
  • Sleeping bag
  • Sleeping pad/pillow
  • Rations/dishes/stove
  • Water/water purifier
  • Bug spray
  • Light jacket
  • Lantern/headlamp
  • Book
  • Camera
  • Boxed wine (minus the bagged wine)
  • 1 or 2 friends and a well behaved dog

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Backpacking, Fishing, Hiking, Mountain Biking, Photography, Swimming

Skill Level:




Trail Type:



10 Miles


Dog Friendly
Easy Parking

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Added by Garren Moore

Programming by week, mountains by weekend.

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