While it's true that the Coast Guard does not have ROTC, there are a few direct commission routes that might interest you.
The State Maritime Academies have Direct Commission Programs into the Coast Guard and so do a few of the Senior Military Colleges. I've included the link. One Program is called "Direct Commission: Selected School," and it requires a 4 week OCS ( shorter than what you'd get if you didn't have military college experience). Maritime Academy grads have a similar program. Here are the links with more information:
http://www.gocoastguard.com/find-yo...ortunities/programs/maritime-academy-graduate
http://www.gocoastguard.com/find-yo...rtunities/programs/direct-commission-programs
If finances are a consideration, you should know that some of the SMCs are generous with aid while others are not. Regarding Maritime Academies, as you live in Idaho, Cal Maritime is the closest. Here is a link with the fee breakdown. It looks like $20k per year, inclusive of everything (tuition, room and board, other fees, personal expenses).
http://www.csum.edu/FinancialAid/Cost.asp
Other maritime schools are SUNY-Maritime, Maine Maritime Academy, Mass. Maritime Academy, and Texas A&M Galveston. There is one on the Great Lakes too, but I can't remember what it's called off hand.
The SMCs which qualify as a "selected school" for the USCG are
Norwich University
Prairie View A&M University
Texas A&M University
Virginia Polytechnic Institute and State University
Virginia Military Institute
Mary Baldwin College, Virginia Women’s Institute for Leadership
You can find a lot of info on these in the Public/Private Military College forum. They are Corps of Cadets programs with similarities to the Service Academies, but are not exactly the same. You'll note that the list doesn't include all the SMCs. The Citadel, for instance, is not listed.
I think these may be more beneficial routes than enlisting in the USCG. The Maritime Academies especially, as the expense is rather reasonable and the education is focused on something that is clearly beneficial to the USCG.