Dan's Outside

Annual Tradition – Predicting the Opening of Tioga Pass Road

Sierra Nevada fans, especially those trying to get to the “east side” from the Bay Area and those on the east trying to get to Yosemite Valley, watch eagerly each spring for the opening of Tioga Pass Road, the trans-Sierra route through the park. The opening date varies from year to year based on a range of factors: the amount of winter snow fall, late storms, the condition of the underlying road, and so forth. Over a period of many decades the average opening has been very close to the end of May. However, I’ve been up there earlier in dry years, and during one memorable wet season in the mid-1990s the pass did not open until July! (I drove over shortly after it opened and was amazed by the amount of remaining snow and by the unbelievable amounts of runoff water everywhere.)

So, when will it open this year? If anyone knows, they aren’t telling – and, in any case, Mother Nature has a way of throwing surprises at us. The NPS does offer periodic updates, and sometimes you can “read between the lines” and get some idea of when the opening might be. (And I understand from some friends who know about these things that the word does start to get out informally a bit before the official announcement. For example, it might help if you knew someone working on the road clearing…)

This winter produced a somewhat above normal snowfall, though not anything record-breaking. The season has lasted a bit longer than usual, with new snow still arriving as we approach the beginning of May. Both of these factors suggest a somewhat later opening than in the past few years. Some work on the clearing is already underway, as per the link above. However, it isn’t enough to simply plow across the pass. Various kinds of debris (fallen trees, rocks, etc.) must be dealt with, turnouts and side roads must be opened, and avalanche dangers must end.

I have no inside information on this at all, but I’m going to guess that we’ll see an opening fairly close to the historical average day of May 29.

April 27, 2010 - Posted by gdanmitchell | Commentary | california, clear, conditions, date, historical, national, nevada, open, park, pass, prediction, road, sierra, snow, tioga, trans-sierra, Yosemite