Hi guys! I am planning a trip from L.A. to Billings & Missoula in mid-April and have a couple of questions that I hope someone might know the answers to.

Mainly I'm concerned about the weather that time of year. I have not been to the northwest at all. I am familiar with mountain driving and with snow driving but not really at the same time. How much snow should I expect and will I need chains?

I haven't decided yet whether to take I-15 through Idaho to get to Billings or if I should use the I-15 to I-80 to I-25 through Wyoming to get there. Any suggestions?

I'm mainly going up there to see a couple of concerts so I'm not counting on any national park visits (as far as I can tell, most are closed still anyhow) but are there any must-see things along that stretch that are open early in the year?

Ok this last question is a little silly but I'm curious about whether or not animals in the road are a problem out that way. I'm used to deer and smaller mammals of course but are elk/moose/bison known for chilling in the roadway? I'm pretty sure I won't see anything at all from the freeway or in any form of city/town but, should I decide to take a backroad anywhere, is that something to be aware of? I just don't want to be, like, that guy that doesn't know honking at a grizzly is a good way to get yourself attacked or anything crazy like that. :)

I think that's it for now but feel free to clue me in on anything I didn't know to ask about!