Heart - Iceberg - Clayton Loop, East Portal Trailhead, Indian Peaks Wilderness Area, Colorado

Heart - Iceberg - Clayton Loop - 10.8 miles

East Portal Trailhead

On the descent from the CDT to south Iceberg Lake

On the descent from the CDT to south Iceberg Lake

Round-Trip Length: 10.8 miles (distance and elevation gains will vary by route)
Start-End Elevation: 9,211' - 12,162' (max elevation on loop)
Elevation Change: +2,951' net elevation gain (+4,080' total elevation gain on loop)
Skill Level: Strenuous
Dogs Allowed: Yes
Bikes Allowed: No
Horses Allowed: No
Related Trails:

Heart - Iceberg - Clayton Loop - 10.8 Miles Round-Trip

Heart Lake, the Iceberg Lakes and Clayton Lake can be linked to form a stunning and challenging 10.8-mile loop through the James Peak Wilderness.

Trail Map | Photo Gallery

Clockwise travel follows South Boulder Creek Trail to Rogers Peak Lake, Heart Lake and up to Rogers Pass on the Continental Divide.

The CDT turns north along the Divide to the Iceberg Lakes Overlook, where you'll drop sharply on best available terrain to the first Iceberg Lake.

The route continues north across the basin to the second Iceberg Lake and north valley wall, which you'll descend to Clayton Lake.

A disused but still well-defined trail picks up at Clayton Lake and drops 900' in .7 miles to rejoin the South Boulder Creek Trail, which runs 2.2 miles back to East Portal.

Despite the modest distance, this is a strenuous and potentially time consuming route with several trail-less miles over treeline and difficult terrain.

Navigation is fairly intuitive from the Divide to Clayton Lake, but you'll have to make a number of critical decisions along the way - specifically the best route down to the Iceberg Lakes, and routing between the Icebergs and Clayton.

The central and south valley offer the most direct route between lakes but terrain is very rugged. Reaching and descending the north valley wall is longer by distance and has its own challenges, but ultimately faster on more accommodating terrain.

GPS points listed below - especially between the Iceberg Lakes Overlook and Clayton Lake - are useful references but distances for each will vary by individual route.

Route Segments:

  • East Portal Trailhead to Rogers Pass (4.85 miles)
  • Rogers Pass to Iceberg Lakes Overlook (1.05 miles)
  • Overlook to Iceberg Lake #1 (.35 miles)
  • Lake #1 to open terrain on north valley wall (1.0 mile)
  • North valley wall to Clayton Lake (.65 miles)
  • Clayton Lake to SBCT (.7 miles)
  • SBCT to East Portal Trailhead (2.2 miles)

An early start, good time management and favorable weather are essential to safe passage across lengthy sections over treeline. Only experienced hikers should attempt this loop:

The South Boulder Creek Trail rises past Moffat Tunnel to the Forest Lakes split (1.25 miles : 9,545') and Crater Lakes split (1.85 miles : 9,925').

It reaches the first of two bridges over Clayton Creek (2.2 miles : 10,038'), where you'll see a faint path blocked by sticks heading up the right side of the creek. This is the disused trail to-from Clayton, and point at which you'll rejoin the SBCT later on.

The SBCT climbs steadily on a variously rocky-rooted path to a cascade (3.48 miles : 10,742') and crosses a makeshift log bridge (3.68 miles : 10,970’) to a large meadow under Haystack Mountain.

It levels in a thinning forest to Rogers Peak Lake (4.05 miles : 11,105') and scales a steep ridge through treeline to Heart Lake and turn-up for Rogers Pass (4.35 miles : 11,316’). The split is not explicitly marked but the path uphill is very clear.

The Rogers Pass Trail climbs sharply with terrific views across the Heart - Rogers Peak lakes basin. It switchbacks several times before leveling in open tundra on the Divide.

There are two signs up here – a dilapidated one for the pass (11,860’), and a new one just steps away with trail information (4.85 miles : 11,875’).

Turn north (right) on the CDT at this second sign and follow double track to the Rogers Pass Trail - Corona Trail split (5.0 miles : 11,880’).

Veer right on the Corona Trail (this is the CDT), which rises over the Heart Lake basin and moderates on a vague path marked by cairns and posts to the Iceberg Lakes Overlook (5.9 miles : 12,115’).

Here you'll head east off the Divide along the lakes' south valley wall ridge and look for best available terrain down (6.1 miles : 11,990').

Reading the terrain correctly - specifically pitch, snow and loose rock - is critical to a safe and efficient descent.

The most direct route drops down a grassy chute to an outcrop about halfway between the ridge and lake (6.18 miles : 11,880'). Keep distance between hikers to avoid falling rocks.

Terrain gradually moderates to the first (south) Iceberg Lake (6.25 miles : 11,710'). Scale a tall knoll / ridge and drop to the second (north) Iceberg Lake (6.6 miles : 11,670').

From here it's a short distance to open terrain along the north valley wall, but you'll have to cross some tedious and time consuming willow and talus to reach it. Pick your poison (a higher route with more scrambling, or more direct route through dense willow) to reach open space on the north valley wall (7.25 miles : 11,420').

Travel eases considerably here on a moderate descent off the wall through alpine meadows and patchy forest to Clayton Lake (7.9 miles : 10,945'). 

A faint trail will appear on the NE side of the lake in a meadow, which quickly clarifies as it heads back into the forest. This disused but still very well defined trail drops 900' in just .7 miles to rejoin the South Boulder Creek Trail (8.6 miles : 10,038').

The trail closely follows the creek; ignore spurs that lead away into the forest. The trail loses clarity as it nears the SBCT, but keep heading down and you'll intercept it. Retrace your steps from the Clayton Creek bridges to East Portal Trailhead (10.8 miles).

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Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N39 54.189 W105 38.666 — 0.0 miles : East Portal Trailhead
  • N39 53.599 W105 39.628 — 1.2 miles : Forest Lake Trail split
  • N39 53.404 W105 40.130 — 1.85 miles : Crater Lakes Trail split
  • N39 53.242 W105 40.395 — 2.2 miles : Bridge and trail split at Clayton Creek
  • N39 52.649 W105 40.553 — 3.0 miles : Steady climb in healthy forest
  • N39 52.240 W105 41.034 — 3.68 miles : Cross creek (right) on makeshift bridge
  • N39 52.277 W105 41.328 — 4.05 miles : Rogers Peak Lake
  • N39 52.409 W105 41.525 — 4.35 miles : Heart Lake and Rogers Pass Trail split
  • N39 52.295 W105 41.834 — 4.85 miles : Rogers Pass - CDT split
  • N39 52.365 W105 41.943 — 5.0 miles : Corona Trail (CDT) - Rogers Pass Trail split
  • N39 52.705 W105 42.041 — 5.5 miles : Trail fades but follows cairns and posts
  • N39 53.083 W105 41.921 — 5.9 miles : Iceberg Lakes overlook
  • N39 53.053 W105 41.768 — 6.1 miles : Drop along south ridge over lakes
  • N39 53.092 W105 41.769 — 6.18 miles : Drop to outcrop on south valley wall
  • N39 53.158 W105 41.759 — 6.25 miles : Iceberg Lake 1
  • N39 53.279 W105 41.750 — 6.45 miles : High ridge between lakes
  • N39 53.359 W105 41.735 — 6.6 miles : Iceberg Lake 2
  • N39 53.438 W105 41.698 — 6.8 miles : Head north to n. valley wall
  • N39 53.593 W105 41.550 — 7.1 miles : Tough push thru willow and talus
  • N39 53.653 W105 41.413 — 7.25 miles : Reach open north valley wall
  • N39 53.524 W105 41.236 — 7.5 miles : Terrain eases down north valley wall
  • N39 53.478 W105 41.121 — 7.7 miles : Transition to meadows and patchy forest
  • N39 53.369 W105 41.004 — 7.9 miles : Clayton Lake
  • N39 53.294 W105 40.756 — 8.1 miles : Steep drop along creek
  • N39 53.312 W105 40.802 — 8.3 miles : Fork, keep right
  • N39 53.252 W105 40.691 — Cascade with flower-covered glade
  • N39 53.208 W105 40.528 — Sharp drop along creek
  • N39 53.242 W105 40.395 — 8.6 miles : Bridge and trail split at Clayton Creek

Worth Noting

  • The Continental Divide Trail (CDT) runs over 3100 miles from Mexico to Canada, 800 of which pass through Colorado. While collectively termed the CDT, many segments have alternative names. The Corona Trail and High Lonesome Trail are two popular segments of the CDT within the James Peak and Indian Peaks Wilderness areas.

Camping and Backpacking Information

  • Permits are not required for camping in the James Peak Wilderness. Contact the Boulder Ranger District (303.541.2500) in advance for the latest trail updates and conditions.
  • There are no designated campsites in this travel zone. Dispersed camping only. Use established sites whenever possible to minimize impact.
  • Campfires are not permitted in the James Peak Wilderness. Gas stoves only.
  • Camp at least 100' away from all streams, lakes and trails.
  • Pets must be leashed at all times.
  • There are several good sites with tree cover around Rogers Peak Lake, and an adjacent lake hidden from the trail. Heart Lake sites are more exposed.
  • Group size is limited to 12 people or people and stock combined.

Fishing Information

  • Fishing is permitted at Heart Lake, Rogers Peak Lake, the Iceberg Lakes, Clayton Lake and all tributaries with a valid Colorado fishing license.

Rules and Regulations

  • Dogs must be leashed at all times in the James Peak Wilderness.

Directions to Trailhead

The East Portal Trailhead is located at the end of Rollins Pass Road, an 8.2 mile dirt road west of Highway 119. Rollins Pass Road is located 4.9 miles south of Nederland, Colorado.

The dirt road is well-maintained but conditions deteriorate when wet.

From Highway 119, turn west on Rollins Pass Road and Keep Straight until it dead-ends at the Moffat Tunnel. Ignore turnoffs that climb toward the pass.

Contact Information

Boulder Ranger District
2140 Yarmouth Avenue
Boulder, CO 80301

Sulphur Ranger District
9 Ten Mile Drive
P.O. Box 10
Granby, Colorado 80446

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