A modest elevation and well-trodden-tourist-track leading to a featureless summit would, upon first glance, make Flattop Mountain appear uninteresting to the mountaineer. But this broad expanse of summit is buttressed by long, sweeping, steep north and south faces that provide excellent year-round climbing in the spectacular heart of Rocky Mountain National Park.
According to the book High Country Names by Louisa Arps and Elinor Kingery, the peak was called Table Top Mountain in 1887 when W.L. Hallett guided Frederick Chapin to its summit. (Those familiar with RMNP mountains will recognize both of those names). The name Flattop was given sometime later but the authors don't mention when or by whom.
The first ascent must be considered unrecorded, as Ute and Arapahoe Indians used a trail over Flattop to cross the Continental Divide for hundreds of years. (Source: Rocky Mountain National Park - A History by C.W. Buchholtz)
The routes I will add to this page are all snow climbs. I know there are some good rock routes on the south face, so please feel free to provide information about these. The mountain is ideally situated to make any outing a circuit, with little or no backtracking. Descent routes can use the standard trail, Tyndall or Andrews Glaciers.
There are three typical options for approaching Flattop, depending upon your climbing destination. All three start at Bear Lake (9.475'). This is one of the main roads in the Park. Take the first left turn after the Beaver Meadows entrance and follow the road to its end.
The trail options to Flattop are:
Depending on the season and conditions any of the above routes can be combined with an alternate descent route to make for a nice circuit outing.
You can descend the standard trail, or walk south along the Continental Divide to Tyndall Glacier, or farther south to Andrews Glacier. The latter is easier and can often (but not always!) be done without requiring an ice axe or crampons. It is also a good snowshoe option.
Combing any of the these with an ascent of Hallett Peak is more icing on the cake!
Flattop is within Rocky Mountain National Park, and all Park regulations apply. The Park's web site will have current rate information.
There are daily as well as annual Park passes. The annual pass is the only way to go for anyone living near the Park. But since you are out climbing and will be entering the Park at an absurdly early hour there will probably be no one there to collect your money.
Please note that no dogs are permitted on any trail in RMNP, leashed or otherwise.
Flattop can be climbed by some route any time of the year.
In summer the major safety concern are the afternoon thunderstorms which can form quickly by noon are a real danger. Avoiding these is why you have entered the park at an absurdly early hour.
In winter you dodge the thunderstorm bullet, but must be prepared for high winds and limited visibility. I have twice been in white out conditions on the featureless slopes of the mountain and was glad to have shot compass readings back to the trail. Avalanches have also claimed lives in the couloirs.
Backcountry camps require using designated RMNP sites.
There is an unpleasant backcountry site called Sourdough near Lake Helene. It is located in forest far from water and with no views of the nearby beauty. (Views of forests are fine, but if you are surrounded by mountains you'd prefer to see them from camp.) There is a nicer site at Odessa Lake. It is also possible to bivouac at the base of Notchtop Mountain.
Typically this peak would be climbed as a day trip, but here is the link to RMNP backcountry camping information.
As usual for Colorado, conditions can range from the easiest of walk ups in summer (my wife and I once strolled to the top on a crystal July day after leaving Bear Lake at 1:00 PM), to howling, white-out blizzards in the winter. Or, the other way around!
The biggest weather hazard are the afternoon thunderstorms which can build with alarming speed and danger. These are common from May through September. The Front Range is also known for ferocious wind, especially in winter.
Longs Peak Ranger Station forecast, elevation 9420 feet, according to the National Weather Service. Of course specific mountain conditions vary wildly over small distances
Estes Park forecast, the gateway town on the east side of RMNP.
Weather charts data from the Niwot Ridge Meteorological site, located at at 3528m (11,572 ft) on Niwot Ridge, some 30 miles south of RMNP. This gives you an indication of recent regional high altitude conditions.
Colorado Avalanche Information Center, more mountain forecasts and current conditions, highly useful avalance information, operates in winter months only.