We had been hearing about the ice on Portage Lake all week. The conditions were perfect. It had been cold enough for a long enough period of time for the entire lake to freeze solid. On top of that all of the snow had been blown off by winds, making it perfect for riding with studded tires.
I had talked to my mom in the morning and she asked what we were doing for the day. I told her we were going to ride our bikes across a big frozen lake and she didn't really like that. She wanted to know how we could be sure it was fully frozen and I told her we just know.
The ice only needs to be about four inches thick (although if it were only four inches thick I would probably pass) and since we have had sub zero temperatures most night over the past month, we didn't think it would be a problem.
And it wasn't. Although I can't say thoughts of falling through the ice didn't cross my mind once or twice. But the awesome views made me forget about that pretty quickly. We rode all the way out to the glacier. I was surprised to see that there was a lot of climbable ice surrounding the lake. I just might have to make a return trip.