In my experience the answer you get depends on who you talk to.
All the front country and telephone staff I've dealt with were absolutely insistent that the ursacks are forbidden and you must use a can. I've had a few debates with them about this over the past few years.
Basically, here is what I have been told when I have confronted the front office staffs with the forest order. You can use your Ursack but if the bear get your food you are liable. If they want you to use a hard sided canister, they would write that order differently.
The Ursack complies with the Inyo's order. I would suggest you e-mail Tom Cohen at Ursack with your concerns. He is very good about responding to correspondence.
