The biomes of the Desert Southwest are ripe for fall adventures as temperatures cool, but they can also provide challenges for the unprepared

For the wilderness enthusiast, the deserts of the Southwest provide incredible outdoor recreation in the autumn months. The daytime temperatures cool from stifling to warm, and precipitation is scarce, which opens up opportunities for the inspired adventurer. Although these environments are home to enchanted trails, epic mountain biking and thrilling whitewater (among many other recreational activities), all desert visitors should understand the biome they are about to enter, and plan accordingly for their fall adventures.  

In the Desert Southwest, one will find two different desert biome classifications: semiarid and hot and dry.  



According to a UC Berkeley article titled “Desert Biomes”, the warm, dry temperatures of the semiarid biome cool down considerably at night. This reduces flora and fauna moisture expenditure caused by perspiring and respirating. Further, it causes condensation of dew, which in turn hydrates its plant and animal inhabitants, making up for the low volume or “concentrated” rainfall. The adventurer can expect warm days, which provide little rainfall and cool nights. Deserts such as Utah’s Arches and Canyonlands national parks, Colorado’s Mesa Verde National Park and New Mexico’s Chaco Canyon National Park roughly fall into this categorization.


The soil in a semiarid biome ranges drastically from finely textured sand to “loose rock fragments” and varies depending on location. On the mountain slope, one will encounter shallow, rocky soil with decent drainage. In the upper bajada (lower slope) one will encounter coarsely textured, rocky terrain that is well-drained, with areas “laid by rock bench.” In the lower bajada (bottom land), the soil is finely textured sand, dry (without subsurface water) and generally with “caliche,” or cemented together, particles. The plant life is brittle, spiny and thorny, with little canopy,” according to UC Berkeley.  

fall adventures
Silva Nesset raises her hands in celebration of the view of the towering pinnacles in the Valley of the Gods, one of the many scenic desert areas in Utah.Jan Nesset


True to its name, the hot and dry biome — according to UC Berkeley research — is “warm throughout the year” and experiences little precipitation as the hemisphere tilts away from the earth. The autumn adventurer can expect hot days and little rainfall. Due to the lack of humidity in the atmosphere, the unblocked solar radiation makes for blistering days, and rapid heat loss makes for frigid nights. Deserts in this category include Arizona’s Grand Canyon National Park and The Great Basin of western Utah and Nevada. 


 UC Berkeley’s ‘Desert Biomes” categorizes the soil as shallow, rocky, and coarsely textured with descent drainage and no subsurface water. Due to water shortages, plant life is “’replete’ (fully supported with nutrients) with water-conserving characteristics… They tend to be small, thick and covered with a thick cuticle…”  

Desert Basics 

No matter what recreational activity one plans to enjoy in these desert biomes, the following are absolute essentials for surviving the hazards:

1. Dehydration:  1 gallon of water per person, per day 

WHY? Bodily water loss due to sweating, breathing and evaporation, dehydration causes one’s regular bodily functions to break down. 

IMPORTANT NOTE: It is best to bring pure drinking water. In the desert, natural “water sources are scarce and often polluted or brackish because of high mineral content,” according to R. Lynn’s “Hazards of Desert Travel.” Even on a river trip, it is a good idea to bring plenty of water. If you’re bringing a filtration system, be sure it is effective enough to adequately protect the drinker from impurities.  

2. Wear clothing to protect against intense sun exposure, including: 

Thin, long-sleeved, loose-fitting shirts offering UV protection 

Thin, loose-fitting pants offering UV protection 

Wide-brimmed, closed-crown hat 



River trip specific: Bimini or umbrella with frame-mount for rafts

WHY? Covering one’s skin is more effective sun protection than sunscreen. Loose clothing allows circulatory air flow, and thus, keeps one cooler.

3. Cold nights  

● Warm layers  

● Warm sleeping bag (if overnighting)  

WHY? Any desert traveler has experienced the surprisingly drastic temperature fluctuations. Night time temperatures plummet and can even drop below freezing.

4. Getting Lost  

● Detailed topographic maps of the intended recreational area (usually available at visitor centers or local businesses)  

● GPS (recommended)  


Mountain Biking: Tires with good tread, spare tubes, repair kit and tools. 

WHY? Navigating the terrain is best with tires offering great traction. The spiny nature of the plants increases the risk of flat tires.  

Rafting Trips:  Sand stake, liberal bow line, Bimini or umbrella

Why? The lack of sturdy trees will make for a shortage of places to tie the raft off. The best soil to sink a sand stake could be a distance from the raft.  

Hiking:  Sturdy hiking shoes with good ankle support. 

WHY? The terrain can be slick with ankle-turning rocks.  

LIS MCLAUGHLIN is an experienced whitewater boater, avid hiker and has a newly ignited passion for mountain biking. When she isn’t outside, she enjoys reading and writing.