Distance: 8.7 km (7.0 DOC hours) - Unmarked route, clear - Moderate terrain
Altitude: 97m to 223m. Gain: 273m. Loss: 149m . Gradient: 3 deg (Flat)
Skills: - Extreme rivers (5/6)

Unmarked route, clear (7/9)
Unmarked route, follows obvious geography (river, spur, trail, etc)

Secondary, unmapped (4/5)
Route not on maps, an alternative recognised access to hut or along range / catchment

Flat (difficulty: 1/5)
Flat

Moderate (difficulty: 3/5)
Low scrub in open or bush / river rocks

None (difficulty: 1/7)
No alpine skills required

Extreme rivers (difficulty: 5/6)
Major rivers - likely to be impassible in all but ideal conditions

None (difficulty: 1/7)
No alpine skills required

No description

Note: Described in the reverse direction to your journey

The track that once ran down Penn Crk / the Otaki River is long gone - overgrown and slipped. The normal route now is down the riverbed. This is a serious trip with multiple deep crossings, many involving swimming. Some swims are 50m+ in length. Hot summer weather and / or a wetsuit are recommended.

From Penn Crk Hut, head north down Penn Crk riverbed. The river is stoney and slow going, and must be crossed multiple times. Once you hit the Otaki the fun begins - the first kilometer is continuous gorge and requires frequent swimming. After that the river alternates between stony walkable flats and gorged swims. I found cold to be a serious problem even in midsummer, even wearing polyprops.

After the final long straight, the winding section shown on maps is encountered. Look out for a stony gravel flat on the left after a right-hand bend at which you are forced to cross from true-right to true-left. A small DOC triangle at the back of flats marks the start of the track climbing to grassy terraces above. On the terrace you join the Waitewaewae track, and can follow this back to Otaki Forks, or head off elsewhere.

I would not attempt this route in the upstream direction.