Directions:

http://www.trailpeak.com/trail-Gwillim-Lakes-near-Slocan-BC-6205
good little link either go to it or:
Directions:
Long, long way on dirt. About 1.25 hours from the highway. 2wd fine until last 2km.
The park access from north (Slocan) and south (Castlegar/Nelson) is different, the following description is from the south.
Take hwy 6 through Slocan Park and watch for Passmore Upper Rd on the left. Take this and cross a bridge, stay straight at the fork, then road curves north and pavement ends. The km markers count backwards from 45 at this end. All major forks are signed 'Valhalla' to keep you on course - soon you are on Little Slocan FSR. At about 22km marker, come to Little Slocan Lake FS rec site - a nice place to spend a free night camping. Meters later, take a signed left for "Drinnon Pass".
KM markers start at 0 now - again, all unclear forks are signed. A little after km 18, stay left, and then right. Low clearance cars may want to park here, as the 1st km of the next 2 to the lot is downright ugly - reminded me of an old creekbed.