Thanks everyone!
He had been talking about going on this hike we did last year again for several weeks, but the weather hadn't cooperated. I figured he just wanted to go hiking again since we hadn't in quite a while due to weather and schedules, but when we got to the trail and were about to start up he got out this note card. I was totally clueless, and I asked him if he had a speech and he said yes.
I said "ok, go ahead!" and listened, and it was really wonderful, about how we have had to climb many mountains in our relationship together and how there will be more in our future but he wants us to always reach the top together - I still have to get the card from him because I want to remember it forever, it was really good. Then he got down on a knee and proposed, and I said yes! I was totally suprised, though we had talked about it many times I wasn't expecting it right now. He was very pleased with himself about that, usually he gets frustrated cause I'm so good at predicting what he has planned or what gifts he buys.