A number of climbs can form on the north-facing south walls of Eagle Creek Canyon when temperatures plummet in the South Lake Tahoe area.
Refer to the directions to Eagle Lake for Eagle Creek Canyon. If the lake is well-frozen, walk across it, or along the south shore of the lake if any doubts. Approach the climbs on (hopefully) snow-covered boulders and talus.
Several lines seem to form on the south wall, reputedly WI3-4.
We climbed only one of them : Cutty Sark
, WI4+, 30m. There is some background on the summer rock routes here
Topropes seemed like they could be set up by walking to the end of the canyon (southwest) and then veering up above the cliffs. Trees might be possible to use as anchors - bring long slings or static rope. Cutty Sark actually had a pair of bolts at the top (no rap rings, so bring extra slings / rings just in case).