From the Sunshine Mesa trailhead, follow the well-defined and relatively flat trail for approximately 3/4 mile until the junction with the Wilson Mesa Trail. Motorbikes can use the trail up until this point.
Continue on the still flat trail as it heads further west, then south into the Bilk Creek drainage to a creek crossing at 10,080. The trail gains almost no elevation for the next mile as it contours around the lower flanks of Sunshine Mountain until it climbs gradually for the last 1/4 mile to reach the creek. In 2019 this section of trail had numerous downed trees and avalanche debris. While this section of trail is open to mountain bikes, we found it not worth the hassle of having to dismount the bikes and lug them over all the timber. If the trail is ever cleared of debris, riding this section may again help shave time off of the approach.
At 10,080' the trail enters a rock field and crosses the creek shortly after. Other trip reports indicate a good crossing via a log jam at this point. In July of 2019 the high water flow appears to have broken up this jam to an extent that would prohibit crossing via the logs. We crossed via a snow bridge left over from an avalanche, but wading across the creek may be the most likely method of crossing in the future.
Once across, locate the Lizard Head Trail and follow it south as it winds it's way up the valley. Along the way, you'll be treated to views of an impressive waterfall as Bilk Creek tumbles down from the upper basin. The well-defined trail switchbacks comfortably through this section as you gain the upper basin around 11,000'.
For those looking to camp, there are few—if any—campsites available in the trees until a single, primitive spot is encountered at 11,060'. This spot is just large enough to house a 2-person tent and is located immediately off the trail on the S/SE side just before it drops slightly to re-join the creek. Above this point there has been extensive avalanche activity. Any other camping would best be had on a small knoll near the lake above 12,000' higher up in the basin.