This trail takes you through a part of the doomed Jurassic beech forest of Kahurangi National Park.
At it's top end near the Flora car park the elevation is nearly 1000 metres. It descends to 100 metres at Upper Takaka over a distance of 34 kilometres. It's a ride for summer as it can get boggy in winter. There are lots of side tracks but the route is well marked. There are a few toilets along the way. Night riding is not allowed.
The first 9 km to Upper Junction are on a gently sloping benched 4wd track. The grade is easy, the forest is other-worldly - right out of The Lord of the Rings.
The next 6 km to Grecian Stream is more difficult - you need advanced riding skills. You're in rugged, remote terrain avoided by most wondering hobbits. You'll have to do some bike carrying and there are stream crossings.
The next 9 km to Barron Flat follows an historic horse track and also needs advanced riding skills.
The final 12 km is mainly on 4wd track. It needs intermediate skills and is outside the national park. You exit onto Cobb Valley Road. Turn right and you'll reach Upper Takaka in less than two kilometres.
There is more information about this trail on the DOC website here: http://www.doc.govt.nz/parks-and-recreation/places-to-go/nelson-tasman/places/kahurangi-national-park/things-to-do/tracks/flora-saddle-to-barron-flat-track/