Summit:
W7O/CE-188
Lava Butte is closed to vehicles in the winter, but open for hiking. You can park at the closed visitor center, or there's an option to pull off 97 near where the Lava Butte road passes the highway. From here there's a very short trail through the brush and you're on the road. We did this option which puts the hike at about 1.2 mi and 540' gain.
The road was mostly clear of snow and ice, with just a handful of spots that had it. We did not need the microspikes we brought in our packs, but had the temps been colder, they would've been neccessary in some spots.