Access is via Ashlu River Road branching of Squamish Valley Road. Past standard Sigurd Creek parking, road curves and goes uphill; plenty of potholes, but still no problem for 2WD. Branch off left on A600 and reach 2WD parking some 15 minutes from last bridge over Ashlu River; this is also site of old river dam. Rest of A600 is almost 2WD driveable, but you need high clearance; bicycle is solid option. Fast walk for about 20 minutes brings you to A-610 branch where you turn left. This is just before significant hill - I actually overshot not believing I reached it so soon, but garmin buzzed in my pocket -- hurah for technology. 4WD parking is about 1km uphill - large clearing just before first big switchback. One could presumably drive longer - but significant washout soon after will make this task rather difficult. I churned my way up, rolling in mind Simon' report. Key is to choose right spot to leave Pokosha trail and head uphill. At the point when A-610 finally peters out some 45 mins from 4WD parking, trail turns sharp right and ascends steeply next to the creek. This is the beginning of large alder slide, which has been generously brushed (by stoked I presume).
Few minutes after you reach far end and re-enter forest. This is the place to leave the trail and head up. You can actually see first orange flag up in the forest if you look carefully. Elevation here is about 900; you have roughly 500 vertical to Coin Lake. There is no trail, but forest is open and route has been quite nicely flagged. Worst part is actually near the bottom; going higher it opens up more and going is fairly easy. Higher up, around 1100-1200 snow starts, and here I lost flags -- possibly they were simply covered by snow. However I had simon and culater foot prints to follow, and that gave me additional piece of mind. Worst part is open slope that needed to be traversed around 1300m; sunshine has softened the snow and I started postholing quite badly. Took me quite a bit of energy (and cursing) to get over. Final bit is steep sub-alpine slope heading up to Coin Lake. Hard frozen snow and I stopped to put micro-spikes; they were great help. Finally I reached the lake - took me 4 hours from 2WD parking and 2 hours from where I left Pokosha trail. Scenery here is simply amazing -- very special moment, that made me forget my aching muscles instantly.