Roads to the telescopes
4 on the map · 3 more worldwide ·
Checked
Observatories need what cyclists need. Height, dry air, and as few people as possible, which in practice means a well-surfaced road to a summit that almost nobody drives up. Some of the best tarmac in the American southwest exists because astronomers had to get instruments to the top of a mountain.
Kitt Peak is the clean case: a state highway that runs out at the observatory gate, which shuts at four in the afternoon so the astronomers get their dark. Haleakalā climbs from a beach to a crater rim at three thousand metres. On Mount Graham the asphalt simply stops, and the telescopes are somewhere further on up the gravel.
None of these roads promises you the telescopes. All of them promise the climb.
The climbs
Kitt Peak the road ends at the gateThe observatory climb: a highway finished in 1967 to haul a four-metre telescope to a summit the Tohono O'odham hold sacred, gated open only from 9 to 4.
Mount Lemmon (Catalina Highway) SkyCenter, 2 mi above the highwayThe reason most riders come to Tucson: 29 miles from saguaro to pine at a metronomic 4 to 6%, built over 17 years by a rotating workforce of nearly 8,000 fed…
Mount Graham (Swift Trail, AZ-366) pavement stops 21.7 mi upArizona's hardest road climb by PJAMM's rating, and its state hill-climb championship for more than four decades: 5,689 feet of gain the race bills as the th…
Haleakalā (sea to summit) summit yes, Science City noWidely billed as the longest paved climb on earth: 58 km from the beach at Paia to 10,023 feet, the shortest ride anywhere from sea level to 10,000.
Not yet on the map
Verified members outside our covered regions — each joins the map when its region does.
- Mount Hamilton (Lick Observatory) The road's gradient was laid out over a century ago so horses could haul telescope parts to the top, which is why it climbs so evenly. Lick keeps a page of advice specifically for cyclists, and the observatory is open to visitors at weekends.
- Roque de los Muchachos Asphalt to 2,426 metres on the rim of the Caldera de Taburiente, serving one of the largest optical telescopes on Earth. A long, quiet, spectacular climb from the sea.
- Mount Wilson The mountain where Hubble found the expanding universe, still working, still reachable by a paved road off the Angeles Crest Highway. It survived the January 2025 Eaton Fire, which reached the mountain itself.