Thanks for your response.

I'm not sure they'd deny me entry (even by request) since I'm a US citizen. But, my husband is inadmissable to the states, so I'm looking to avoid crossing, or even going to the border guards.
So, I'm trying to figure out of going into the states is a *necessary* part of the process. I am guessing no, because people can "land" from inside Canada.
Just nervous and trying to make sure I have all my bases covered and that I understand the situation correctly.

I don't want to accidently put myself or my husband in a sticky situation.
I just looked at some Google maps of a few of the stations, and several of them have spots where you can turn around and go into the Canadian gates, without going across to the American side. So I think it'll be okay.
Thanks.

This is from what i know .............
So, I'm trying to figure out of going into the states is a *necessary* part of the process. I am guessing no, because people can "land" from inside Canada. This is for a lot of ppl under refugee class and has nothing to do with your scenario.
Yes, you need to enter canada from another country...US is the cheapest option.
They will check for the US exit stamp when you enter Canada
This is what i did, went to Niagara falls..walked the bridge..entered US immigration, got an entry stamp in my PP and made a U-TURN ( they will guide you ) and walk back to the Canadian Immigration and they checked where i came from. When i asked the IO the same question, she said..you can not come out of "no-where" to enter Canada legally.
Thus the need for a landing PR to come from a source country ( unless its a complicated case and you do not have a source country nor a passport )
I just looked at some Google maps of a few of the stations, and several of them have spots where you can turn around and go into the Canadian gates, without going across to the American side. So I think it'll be okay. You can try this but its a gamble...depends on the IO who processess the entry.
If i were you, and i was in this position i applied for a US visa just to land...but i have read cases which did not do it..depends on which IO takes care of you when you land.