Slow Travel
Mountain Passes Open And Close On A Working Calendar
Seasonal highway closures in the American mountains follow snowpack and plowing capacity rather than fixed dates, which makes spring itineraries harder to plan than winter ones.
Many high roads in the western mountains are closed for a large part of the year. The opening date is a working estimate that moves with the snow.
Closure is decided by avalanche risk as much as by depth
Roads are gated when keeping them open becomes unsafe or uneconomic, and slide paths crossing the route are usually the deciding factor.
Plowing a road that will be buried again by the next storm consumes equipment needed elsewhere, so agencies close rather than fight it.
Some passes close on a scheduled date each fall regardless of conditions, because the crews and equipment are reassigned to lower-elevation priorities.
Spring opening is a plowing project
Clearing a high pass can take weeks, with crews working from both ends through drifts that are many times the height of the equipment.
Avalanche control precedes the plow, and unstable slopes above the road are brought down deliberately before crews work beneath them.
Progress is reported publicly on some routes, which is more useful for planning than any historical average opening date.
Historical dates are a guide and not a promise
A pass that typically opens in late spring can slip by weeks after a heavy winter, or open early after a light one. The variation is large enough to break a trip plan.
Booking non-refundable lodging on the far side of a pass before it opens is the standard version of this mistake.
Building an alternative route into the plan, usually a much longer detour, is the practical response for anyone traveling in the transition months.
Opening the road is not opening the country
A cleared road often runs between snowbanks with trails beneath deep snow on either side, so arriving at the trailhead does not mean the hike is available.
Campgrounds, restrooms and water systems open later than the road, because pipes cannot be charged until the risk of freezing has passed.
Snowmelt also raises creeks, so the weeks right after opening are the hardest time of year for crossings on the trails the road provides access to.
Some closures never reopen on the old schedule
Storm damage, washouts and slides can close a route for a season or longer, and repairs on remote highways compete for funding against busier corridors.
Fire closures behave differently again, since burned slopes shed debris for years afterward and a road below one may close repeatedly during rain.
Anyone planning around a mountain road should treat the state transportation department's current status page as the only authority, and check it the morning of travel.
Questions readers ask
Can I book a bothy?
No — open shelters cannot be reserved, which is precisely what makes them reliable in an emergency. Carry a tent as a backup on busy weekends.
Are shelters free?
Open bothies generally are, maintained by donation and volunteer labour. Staffed refuges charge, usually with a discount for members of affiliated alpine clubs.
