Ten years ago this week my husband and I got married in Utah and drove to San Francisco for our honeymoon. That was a year that the ski resorts around Lake Tahoe wished that it would stop snowing--no one could get to them. We had no chains. We somehow, with absolute vanity, chose to ignore all the signs that said "Snow Chains Required Ahead." I thought that it was a go at your own risk kind of thing. So, after 20 miles of warning signs, and 10 decent opportunites to stop and buy reasonably priced chains, we were stopped by police and told we could not continue without chains. We got off at the last possible exit and bought what was there --cheap quality, $50 chains . Later that week I saw the same chains for $24 at Wal-Mart. We did end up being glad for those chains. We went over that pass, just behind a snowplow, at 5 miles an hour.
So, moral of the story: Get chains now.