We were on the Sheep Glacier route from June 20th through the 27th, of 2014. Diurnal showers every day for the duration would severely limit our visibility, especially after 2pm or so. Mornings tended to be drier with better visibility, especially below 10,000'. After summiting on the 24th, a system moved in from the SE of Mt. Sanford and we received a solid 24" of snow in a 24 hour period at our 13,000' camp. Be prepared to navigate in poor visibility or you will not move on days like that. We wanded the entire route but heavy snow was enough to bury many wands. Bring a GPS. Best map resource I could find was the Gulkana A-1/B-1 from 1959, printed them out at Fedex Office, seemed pretty accurate. Also be aware that magnetic variation has changed a lot, it is now roughly 20 degrees East.

Trip report can be found at the Summit Sensations website.

~John