Page Type Page Type: Mountain/Rock
Location Lat/Lon: 37.59175°N / 107.61591°W
Additional Information County: La Plata
Activities Activities: Hiking, Mountaineering, Scrambling
Seasons Season: Spring, Summer, Fall
Additional Information Elevation: 13310 ft / 4057 m
Sign the Climber's Log


Aztec Mountain Aztec Mountain as seen from a campsite in Chicago Basin
East Ridge of Aztec East Ridge of Aztec
Aztec Mountain
is a low 13er towering above Chicago Basin. Most people traveling to Chicago Basin have a goal to summit 14ers: Mount Eolus, Sunlight and Windom Peak. Aztec Mountain is rarely summited, since it is not even a bicentennial (highest 200 in Colorado) peak, or a tricentennial peak. However, it offers great views and a nice scramble. The access to Chicago basin is a long one, you can either take the historic Durango Silverton train or hike in from Purgatory Flats Trailhead and along Animas River. The hike in from Purgatory is very long - 16 miles into Chicago basin. 2018 year was dry, there were wildfires, so the train was closed to backpackers. We had to hike in. The advantage of the long walk was that normally a popular and crowded Chicago Basin was relatively empty (about 2 more parties). Expect a lot of mountain goats poking around and some can be very inquisitive and will get very close to you.
Guide to the Colorado Mountains with Robert Ormes (sort of a bible of Colorado Mountains) provides only a brief mention of Aztec Mountain.  "Columbine Pass is the way to approach Aztec Mountain (13,310'). Go 1.5 miles south, then boulder hop along the mountain's tedious east ridge."  Colorado Rank: 385
Class: 2+
Weminuche Wilderness: At 3/4 the size of Rhode Island, the Weminuche Wilderness is the largest wilderness area in Colorado. The Weminuche spans the Continental Divide, North America's geological backbone, with its headwaters diverted to both the Pacific and Atlantic oceans. With an average elevation of 10,000 feet above sea level, the Weminuche is rugged country.
Parent Lineage: Jupiter Mountain Nearby Mountains
  • Mt. Kennedy (unranked)            0.63 miles
  • Bullion Mountain (unranked)    0.80 miles
  • Silver Mesa (unranked)              1.06 miles
  • Florida Mountain (unranked)    1.37 miles
  • Hope Mountain (unranked)      1.46 miles
  • Jupiter Mountain                           1.94 miles
  • Mt. Valois                                   2.09 miles
  • Mount Eolus                                 2.12 miles
  • McCauley Peak                         2.12 miles
  • Peak Eighteen (unranked)       2.15 miles
  • Grizzly Peak C                           2.17 miles
  • "South Windom" (unranked)   2.23 miles
  • Glacier Point (unranked)         2.37 miles
  • Echo Mountain (unranked)     2.42 miles
  • Windom Peak                              2.43 miles
  • Peak Eleven                              2.60 miles
  • "Sunlight Spire                            2.63 miles
  • Sunlight Peak                              2.69 miles
  • Peak Sixteen (unranked)        2.72 miles
  • Peak Fifteen                               2.78 miles

Getting There

Crossing Animas River Crossing Animas River
Frequent mountain goats Frequent mountain goats in Chicago Basin
There are several options to get to Chicago Basin: the easiest is to take the historic Durango Silverton train and exit at Needleton. However, this train operates only seasonally and during certain times such as summer 2018 it may not take backpackers. Expect about 5 miles hike in into Chicago Basin from the train stop. 
Approach on foot to Chicago Basin: The closest way is from Purgatory Flats Trail. From downtown Durango, head north on Highway 550 approximately 25 miles to Tacoma Drive. Look for the entrance to Durango Mountain Resort on the left side of the road, and Tacoma Drive is directly from the entrance on the right (east) side of 550. Take a right onto Tacoma Drive, also signed for Purgatory Creek TH and follow the road for less than 1/4 mile and you will see a dirt parking lot on the left next to a small lake. Park here (free) and the TH is right across from the parking lot next to a house. 
Trail: The trail is easy to follow passing by a registration sign for the Weminuche Wilderness Area. After the sign, the trail descends down a number of switchbacks and then it follows along side Purgatory Creek. After about a half-mile, the trail crosses over Purgatory Creek on a make shift stone pathway. After crossing the creek, the trail gets steeper for a bit as travels through a number of aspen grooves. After about 1.2 miles, the trails begins a series of switchbacks as it makes a final descent to Purgatory Flats. At Purgatory Flats the trail splits left and right. Turn right here and head downstream Cascade Creek and towards Animas River. It is about 4.5 miles to get to the bridge over Animas River. 
Animas Trail: It is about 7 miles from the bridge over Animas to the turn off for Chicago Basin. The trail continues upstream along Animas River on an easy to follow trail. It gently ascends, it is mostly in wooded areas and there are multiple sites for camping here. It is hard to spot the train since it is wooded.  The turn off for Chicago Basin is signed and from the intersection is about another 4.5 miles. The trail turns east here and it gets steeper. Chicago Basin is beautiful area, wide and surrounded by many mountains. Expect to see abundant wildlife especially mountain goats and deer. 
The Durango-Silverton Train The Durango-Silverton Train


East Ridge of Aztec Mountain East Ridge of Aztec Mountain
Scramble on east ridge Scramble on east ridge
I believe that each mountain has many options to reach its summit. We had no beta information with us for Aztec and it was sort of an "add on" peak since we had a half day time (we have done Peak Fifteen on this trip and Peak Eleven). 
I looked at the map, checked the mountain from the campsite and thought that the easiest way up while avoiding the scree would be to follow a trail up to Columbine Pass, from there to start a traversing trail towards Trimble Pass. After a slight descend from Columbine Pass and passing a boulder field, we left the trail and headed for a grassy ramp, which took us all the way to the ridge. We followed this ridge over an unnamed unranked sub peak and from here we followed the east ridge to the summit of Aztec. The walking was slow since there was a lot of loose rocks and up and down scrambling. It was not technically challenging and the route finding was obvious.  The summit of Aztec Mountain had a nice cairn, but no summit register. 
Descent: We descended the east ridge of Aztec to the area marked with a cairn and wooden stick. There was a scree couloir, which did not appear very steep. We followed this into Chicago Basin and intercepted an old mining trail, which took us to a trail leading from Columbine Pass to Chicago Basin. 

Red Tape

Aztec Mountain is located in the Weminuche Wilderness, so wilderness rules apply. Leave no trace. 


-- Group size is limited to no more than 15 people per party.  -- Camping is prohibited within 100 feet of any water source.  -- Camping and all campfires are prohibited at the following locations:  1. within 200 feet of Archuleta Lake, Fourmile Lake, and West Ute Lake  2. within 1/2 mile of the north shore and 1/4 mile of other shores of Emerald Lake  3. within 1/4 mile of Little Emerald Lake  4. between the shore and Flint and La Osa Trails at Flint Lake; and within 200 feet of the west and north shores  5. in Needle Creek drainage at Twin Lakes  6. in the hot springs area at West Fork (Rainbow)  -- Campfires are also prohibited in all of Needle Creek Drainage (including Chicago Basin) and Vestal Basin.  -- Do not shortcut switchbacks.  -- Pets must be under verbal control or leashed at all times.  -- Disposal of human waste and wash water is prohibited within 100 feet of any water source.  -- As with all designated Wilderness areas, mechanical transportation (including wagons, game carts, wheelbarrows, bicycles, or other vehicles) is prohibited. 

When to Climb

The approach is hard and obviously the easiest time to climb Aztec Mountain is in the summer or early fall. Other seasons provide difficult and long approach and winter high avalanche danger. 
The train between Durango and Silverton operates only seasonally during the summer and early fall, winter means at least 16 miles of backpacking in. 


There are wonderful campsites in Chicago Basin area. Primitive camping, plenty of water sources from streams. 

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