Distance: 3.4 km (3.0 DOC hours) - Tramping track - Easy-moderate terrain
Altitude: 599m to 1315m. Gain: 720m. Loss: 19m . Gradient: 12 deg (Moderate-hard)
Skills: Alpine weather (2/7) - Occasional rivers (3/6) Winter - Snow/ice underfoot (2/7)

Tramping track (4/9)
Cut, marked tramping track: natural, rough ground surface

Primary, mapped (1/5)
Formal route, on maps, principal access to hut or along range / catchment

Moderate-hard (difficulty: 4/5)
Continuous moderate climbs

Easy-moderate (difficulty: 2/5)
Tussock / river-gravel / open bush / cut track

Alpine weather (difficulty: 2/7)
Tramp on open tops, exposed to alpine weather

Occasional rivers (difficulty: 3/6)
Occasional rivers - impassible after heavy rain

Snow/ice underfoot (difficulty: 2/7)
Snow/ice likely on track

Route as far as Tarn Biv does not climb significantly once above the bushline, and is not exposed to falls on the tops, so generally is a viable winter route on flat snow tops. I'd take an ice-axe just in case. And a very warm sleeping bag!

From Daphne Biv the route heads 200m up the creek bed (at least 2 crossing recommended, but could be done on the TL with some scrambling) to the sidecreek shown on the map. River is knee deep in normal conditions, but can become impassible after rain.

Track markers indicate the start of the steep climb to Black Ridge. Track is steep and suffers from slipping and windfall as it climbs the initial face. Going improves on the spur on a solid surface in mature bush. A good, steady 600m climb on a cut, marked track.

Emerge onto rocky tops 200m before pt1285. As with Longview, this section of the range gets very strong winds in a westerly - stronger than on the main range. A signposted track junction on pt1285 indicates the alternative track dropping east to the park boundary lower down the the Tukituki. (1-2 hrs Daphne -> pt1285)

Tarn biv is 1km beyond across mostly flat, exposed tops. The biv is tucked to the east of the small summit ridge, and gets some shelter from the westerly, but it is an exposed place. (30 mins - 1 hr pt1285 to biv)

Note: Described in the reverse direction to your journey

From Tarn Biv, pick up the unmarked route running south along the ridgeline just wets of the biv. At pt1285 is a signposted track junction with a track dropping east to the lower Tukituki. Continues south down Black Ridge and into the bush. Here a good marked,cut track begins and descends the obvious spur. The last 200 vertical meters to the river are down a steep face, and the track becomes rough with windfall and slips.

The track hits the river 200m upstream of Daphne Hut. Normally, cross the river and descend on good flats to opposite the hut,, recrossing there. If the river is up, you could sidle the eastern bank, but it would be a scramble.