We did the entire Imp Trail, starting at the northern trailhead. It was very icy. We used full crampons right from the parking lot and only took them off about a mile from the end of the hike. Turns out that was premature, because as soon as the trail turned from a southerly-facing trail to a more westerly-facing trail, it was all icy again. We put Microspikes on at that point but could easily have just put crampons on again.

Microspikes would definitely NOT have cut it on this hike. The ice formations were very beautiful but treacherous.

The first stream crossing was tricky, since it was fast-moving open water but there was enough ice to make it deep water and slippery. Use much caution! Poles will definitely help on the stream crossings, though I put away my poles very early into the hike as they were not getting any purchase at all on the icy trails.