Twenty-seven miles and 7,200 feet from Idaho Springs to 14,138 feet — the highest paved road in North America.
About this ride
Colorado 5 climbs from Idaho Springs to just below the 14,265-foot summit of Mount Blue Sky, renamed in 2023 from Mount Evans. It is the highest paved road on the continent, and it has been raced since the 1960s as the Bob Cook Memorial hill climb.
It divides in two. The first 13 miles to Echo Lake are a steady 4-6% through forest — comfortable enough to go out too hard, which is the classic mistake here. Above Echo Lake the road narrows onto CO-5, the trees thin, and the grade stops relenting. Summit Lake sits near mile 22 at about 12,800 feet; the last three miles gain nearly 900 more, on roughly 60% of the oxygen you get at sea level.
Nothing about this climb is steep — 5% on average, under 9% at its worst. It is decided entirely by altitude and by the clock.
Local notes
water
Water and facilities
Echo Lake at mile 13 is the last reliable water and the last facilities. Carry everything you need for the 14 miles above it, and for the descent.
weather
Storms and cold
Afternoon thunderstorms are the real hazard, not the grade. Start early enough to be off the summit by midday. The top is cold in any month — a summer summit can be near freezing with wind — so bring more layers than feel sensible at the bottom.
safety
Altitude
Above 13,000 feet the altitude is the limiting factor, not the legs. If your head goes heavy, stop, drink, eat and let your heart rate settle; a few minutes recovers more than pushing through does. Acclimatise for a day or two beforehand if you can.
traffic
The road above Echo Lake
Narrow, no shoulder, and largely without guardrails. The traffic is sightseers who are also looking at the view. Mountain goats and bighorn sheep are common near Summit Lake and step into the road.
general
The descent
Its own event. The pavement above Echo Lake is cracked, rippled and potholed, and it is often wet in the afternoon even when the morning was dry. Take it slowly down to Echo Lake; below there it is fast and fine.
seasonal
When it is open
The upper road is gated for most of the year, typically opening around Memorial Day and closing in early autumn. Dates move with the snow, and access rules have changed in recent years — check the current position before travelling.
