Rocky Mountains Backpacking – Thunder Lake
Whether you've joined us on our Rocky Mountain National Park North Inlet itinerary or if this is your very first backpacking adventure, our backcountry exploration of this incredible park continues with our journey to Thunder Lake. After an initial meeting and orientation in the lively city of Boulder, CO, our exploration begins in the southeastern corner of Rocky Mountain National Park, our nation's tenth national park. Deep in the Wild Basin Area, we'll make our home in the forest selecting a picture-perfect site from which to explore the nearby mountains and lakes. Our basecamp set-up allows us to climb, unencumbered by heavy packs, to the reaches of crystal clear alpine lakes nestled in the snow-capped peaks surrounding us and traversing a valley on an off-trail route. With a pace that's perfect for shutterbugs and wildflower aficionados, we'll revel in the beauty of the iconic high country as our guides share their comprehensive knowledge of the park's natural and human history, trails and little known secrets. Whether this is your first or your fortieth adventure to the Rocky Mountains, this itinerary will provide the perfect weekend wilderness escape.
We also offer a Rocky Mountains Backpacking – North Inlet trip that runs on alternating weekends and explores a different section of the park.
Rocky Mountains Backpacking – Thunder Lake Itinerary:
Day 1 Meet at the REI store in Boulder, CO for a trip orientation. Enjoy dinner together while eagerly anticipating the adventure ahead!
Day 2 Stunning waterfalls and majestic peaks await as we journey into the backcountry.
Day 3 With only a daypack on our back, we'll explore magnificent alpine lakes, marvel at the incredible geological history of the Rockies, and possibly even hike up to the backbone of our continent.
Day 4 Another sunrise savored with our morning coffee, our final hike brings us back to our trailhead before shuttling back to Boulder.
Although we do our very best to adhere to the schedule above, this itinerary is subject to change for numerous reasons beyond our control including weather and terrain conditions. This trip is operated rain or shine.
Contact REI Adventures prior to purchasing your airline tickets to confirm the trip has the minimum number of participants required to operate.
Professional instruction and guiding; all meals as noted in the daily itinerary; snacks; group cooking gear; group first aid kit; water filter; transportation from host hotel to store meeting (upon request); transportation from host hotel to trailheads; campsite and permit fees.
Transportation from your hometown to group meeting point; insurance of any kind; first night accommodations; energy drinks; alcoholic beverages; soft drinks; guide gratuities and items of a personal nature.
This trip is rated Vigorous [4] as we plan to hike for 5-8 hours per day most days on steep, rocky, sometimes exposed terrain, gaining and/or losing from 1500 to 2500 feet in elevation some days. We will carry packs weighing 30-35 lbs while we hike, and will consistently be at elevation of 8,500 feet or more. To maximize your enjoyment of the trip we suggest that you engage in a regular exercise regimen beginning at least three months prior to your departure. Most important to your enjoyment of the trip is your overall fitness level.
The high country of Rocky Mountain National Park is well-known for extreme weather patterns. These patterns can change rapidly due to elevation, slope, and exposure. Afternoon thunderstorms and wind are typical of most summer days. Always be prepared for a sudden temperature plunge of 10-20 degrees Fahrenheit and a sudden rainstorm. A wide deviation between day and nighttime temperatures is also characteristic of mountain weather on Colorado. Daytime temperatures can range between 80-50 degrees F, with evening temperatures dropping into the 30s - 40s.
Denver International Airport, Denver, Co. - 25 minutes
This trip is subject to the booking information set forth in the current REI Adventures Weekend Reservation Information. Please read this information carefully and call us if you have any questions. A full gear list and detailed pre-trip information is sent upon sign-up. We highly recommend the purchase of travel insurance through REI Adventures. If coverage is purchased at the time of your initial reservation, the 'Pre-existing Conditions Exclusion' is waived (certain exclusions apply).
We look forward to having you join us for the trip of a lifetime! Why wait? Space is limited, reserve your adventure today.
Rocky Mountains Backpacking – Thunder Lake
The key to staying comfortable while on an active trip is layering. To get maximum comfort with minimum weight, you need versatile layers that mix and match to create the right amount of insulation, ventilation and weather protection. Try to bring only what is necessary—this will help you and the field staff.
Gear Checklist
- Tents (3 season, 2 person)
- Cooking gear
- Stoves and fuel
- Water filter
- Group first aid kit
- Bear canister
- Backpack: large internal frame or external frame (4000 – 6000 cubic inches)
- 20L – 30L day pack
- Pack cover (waterproof)
- Sleeping bag (rated around 20-35 F)
- Sleeping pad
- Rain jacket and pants (lightweight waterproof and breathable)
- Lightweight down or synthetic jacket
- Hiking boots (heavy duty, waterproof, broken-in & should rise above ankle)
- Comfortable closed toed camp shoes or cross trainers to be used at camp and on day hike
- Hiking pants (quick-drying, lightweight; zip-off legs are great. No jeans!)
- Hiking shorts (quick-drying, lightweight)
- T-shirts (synthetic)
- Long sleeve shirt (synthetic)
- Underwear
- Hiking socks (wool or synthetic)
- Synthetic Sock liners (optional)
- Sun hat with wide brim
- Mid-weight fleece jacket or wool sweater
- Mid- or lightweight thermal bottom made of synthetic or wool
- Down jacket or vest (optional)
- Wool or fleece hat (optional)
- Wool or fleece gloves (optional)
- Powdered drinks
- Headlamp with spare batteries and bulb
- Plastic bowl, spoon, travel mug with lid
- Sunglasses and retainer strap
- Sunscreen (small amount not the whole bottle; min SPF 25)
- Lip balm (unscented)
- Personal medications
- Toothbrush & trial-sized paste
- Pack towel and/or washcloth
- Personal first aid kit (small and light with personal medication)
- Lighter
- Travel size wet-wipes
- TP system: toilet paper (not a full roll) & 1 Ziploc quart baggie & 1 Ziploc gallon baggie and plastic trowel
- 1 large plastic garbage bag
- Insect Repellant
- Bandana
- Two 1-quart water bottles or hydration system equivalent (if relying on a hydration system, in case of punctures, clogs, or bladder failure, we highly recommend bringing a lightweight 1-quart bottle as backup)
- Trekking poles (highly recommended)
- Pocket knife or small multi-tool
- Compass
- Ear plugs
- Journal & pen
- Camera and film - think weight
- Favorite snacks or energy food (snacks are provided but if you have a preference and would like to bring something, please make sure it is small, lightweight and will easily fit into a shared bear canister)
Feel free to give us a call at (800) 622-2236 should you have any questions regarding the gear list. The staff at our stores and Direct Sales (800-426-4840) will also be happy to help you with gear questions. Or check out www.rei.com/learn. The Expert Advice section on our "Learn" page has great information to help you prepare for your trip.





