Continued access to Box Canyon is at the pleasure of the private landowner. Please...no dogs, no defecating in canyon. Pack it out. Pack it all out.
The best single book for Maple Canyon Ice Climbs is Jason Stevens' Maple Canyon Ice Climbing, available at area specialty equipment shops (or perhaps from him directly if you contact him on this site). Read it, especially his section on vehicular access issues.
All of the climbs in Maple Canyon absolutely require snow to provide moisture for the melt/freeze which forms these climbs, so snow-covered roads are pretty much a given. Plan to hike or skin up the road. It's a nice warm-up for the climbing, and will alleviate a lot of opportunities for a headache.
This information is a public crowdsourcing effort between the Access Fund,
and Mountain Project. You should confirm closures, restrictions, and/or related dates.