Reposting from 2016. Phu Luang Wildlife Sanctuary is at the Phu Luang mountain area in Loei province and is part of the Luang Prabang mountain range Eco-system. Although the Phu Luang mountain is accessible from different places, the wildlife sanctuary entrance is at the north side. Access to here is a road from route 21 (203) between Phu Rua and Loei city. It takes you about 14 km to the entrance of the National Park. Entrance fee for Thai is 20 Thai baht while non-Thai have the privilege of paying 10 times as much (200 Thai baht).
After the entrance it is another 14 km driving to the HQ at 1.400 meter high. Be aware that the last 7 km of this road has some very steep parts. I would not recommend to drive this with a mini-van. Actually a 4WD car would be best. Be also aware that in the raining season access to the park is closed. At the HQ op top are some simple rooms in bungalows and tents for rent. The tents look good and well taken care of. You even have your own toilet! From the HQ you can make walking tours with a park-ranger as guide. There are 2 walking treks to be made, one of 5 km (one-way) and another of 2 km (a looping). Both trails are about nature, flowers and if your lucky wildlife like monkeys, birds and elephants.
We were here for a 1 day visit, but it would be best to arrive in the afternoon. Then first make a short walking trip and stay overnight. Then the next day wake-up early and make the longer walking trip. There is no public transport to the park or nearby so you will need your own transport or arranged trip.