Hidden Gems of Pioneer Basin, John Muir Wilderness, California

The route and itinerary presented here provide a general plan for our seven-day trip. Adjustments may be necessary to account for changes in weather or trail conditions, the progress of the group, and the availability of campsites. Flexibility and a positive attitude are pre-requisites for the trip.

Day 1: We will meet at 4:00 p.m. at a campground near Mosquito Flat trailhead, which is just west of Bishop, California and up Rock Creek Canyon. After introductions, we will inspect the equipment, review our hiking route, and have dinner. Each participant is encouraged to bring an appetizer that can be shared with the rest of the group. 

Day 2: Our trip will start with an early breakfast provided by the trip leaders. After breakfast, we will distribute group equipment and bear canisters and will start hiking up toward Mono Pass and spend the night at a lake below Mono Pass. Because of the initial high elevations, this first day of travel is intentionally short to allow us to acclimate to the thin air and get comfortable with our packs and gear. At first, the gentle trail follows the natural moraines but soon reveals 12,800-foot Mount Starr and the headwall that becomes Mono Pass. We plan to arrive around lunchtime to get a good group campsite and explore the classic alpine lake and its surroundings. 3 miles, 1,100-foot elevation gain.

Day 3: We awake to the sunlit peaks that guard today’s ascent over Mono Pass. After breakfast we begin what appears to be a formidable climb up the canyon headwall that soon opens up to a sprawling vista, revealing our playground for the next three days. We will descend to Trail Lakes where we will set camp for the night at about 11,200 feet. 3.5 miles, 1,200-foot elevation gain.

Days 4-5: On Day 4 we cross Mono Creek and head up-canyon to the highlight of our trip, Pioneer Basin. We will spend two days in this sprawling basin with Mts. Stanford and Huntington to the east and Mts. Crocker and Hopkins to the north and west. Pioneer Basin is filled with a cascade of glaciated lakes, affording a wide-variety of easy-to-moderate day hikes. If you prefer a more leisurely time on the layover day you can rest in camp, fish, read a book, or swim. Summiting one of the surrounding 12,000-foot peaks is an option, too, for those seeking more adventure. Day 4: 3.5 miles, 1,000-foot elevation gain.

Day 6: Refreshed after our layover day, we’ll make our way out of Pioneer Basin, once again crossing Mono Creek to the south and then head east following a use trail to Golden Lake. We’ll spend our last night in the wilderness on the shores of this boulder-strewn lake in a remote canyon of Mono Pass. 3.5 miles, 1,100-foot elevation gain.

Day 7: On our last day in the wilderness we may track a short cross-country segment out of Golden Lake to connect to Mono Pass or re-trace our tracks back to the Mono Creek, and then continue on a rigorous hike up to Mono Pass. As we round the base of Mt. Starr, we’ll be treated to a sprawling vista of the basins that we have traveled through over the past six days. As we cross the Sierra Crest, we will encounter steep, downhill switchbacks by Ruby Lake before we reach the Mosquito Flat trailhead. Please give yourself enough leeway when planning your return flights as the precise ending time is not guaranteed. 6 miles, 1,300-foot elevation gain.

Getting There

The closest major airport is in Reno, Nevada, 210 miles (four hours) to the north. The closest major city is Bishop, California, which is a six- to seven-hour drive from the San Francisco Bay Area or Los Angeles. Plan your travel arrangements so that you arrive at the camp no later than 4:00 p.m. on Day 1. Participants are encouraged to share rides. The leader will provide a trip roster before the trip to assist in your planning. 

Please do not make non-refundable travel arrangements until notified to do so by the trip leader.

Accommodations and Food

The leaders will provide all meals, including dinner on our first day (Day 1) and concluding with lunch on our last day (Day 7). Meals will provide a balanced diet that will satisfy the caloric demands of the trip. We can accommodate vegetarians. If you have food sensitivities, please let the leader know when you apply. We will have a gravity water filter for the entire group to use at camp. You are responsible for any non-group personal water treatment.

All backcountry camps will adhere to the land agency regulations and guidelines and will follow the principles of Leave No Trace.

Trip Difficulty

This trip is rated as Moderate with a difficulty level of 3 on a scale from 1 to 5, where 1 denotes the easiest and 5 the most difficult. It requires good conditioning prior to the trip, excellent health and fitness, and appropriate equipment to protect against unexpected weather conditions. We will average 3-5 miles per day with the longest day being 6 miles. We’ll be hiking and camping at elevations above 10,000. It is strongly recommended that you arrive at the campsite at least one day before the trip and complete a short hike in the vicinity to allow your body to acclimatize. 

Participants must have previous backpacking experience to be approved for the trip. Portions of our trip will be off-trail. Participants must maintain a regular fitness program, including practice hikes with a 40-pound pack and boots, starting at least two months before the trip. Out of fairness to all participants, the difficulty of this trip requires a careful screening process by the leader. 

August in the High Sierra typically brings beautiful weather conditions. However, backpacking in remote wilderness areas requires that we be prepared for extreme conditions that can occur at any time. At lower elevations temperatures can reach 80 degrees, while nights at high elevations can dip into the 20s. Thunderstorms or snowstorms can occur at any time of the year, with sudden cloudbursts of wind, rain lightning, and hail.

Equipment and Clothing

On Sierra Club outings, you must furnish your own personal equipment, including items such as clothing, boots, backpack, sleeping bag, tent, a "basic" first-aid kit, toiletries, and eating utensils. Your equipment and clothing need to be suitable for the typical High Sierra changing weather which often sees large variations in temperatures and unexpected precipitations. The leaders will provide all shared group cooking equipment (including stoves, cookware, and cooking utensils), a group first-aid kit, a gravity water filter for group use and bear-resistant food storage canisters. 

At the start of the trip, you will be given a full bear canister and a portion of the group gear, weighing approximately 16-18 pounds. Your personal gear should not weight more than 20 pounds excluding water, so that together with 2 liters of water, the bear cannister and group gear your total pack weight should be no more than 40 pounds.

Wearing sturdy broken-in boots with good ankle support will be critical to your ability to move across a variety of terrain with ease and comfort. Additionally, we require that you bring a sleeping bag that will keep you warm at temperatures of 15-20 degrees Fahrenheit, waterproof rain jacket and pants, a tent, and a backpack. Some of the group equipment is relatively bulky, particularly pot sets and bear canisters. Your backpack should be sufficiently large to carry an item about the size of a full paper grocery bag (alternatively, four or five one-gallon milk jugs) in addition to your personal gear. The leader will be happy to send a detailed gear list after participants sign up for the trip.

References

Maps:

• U.S.G.S. 7.5-minute quadrangles: “Mt. Abbott”
• Tom Harrison Maps: Mono Divide High Country

Books:

• Arnot, Phil, High Sierra John Muir’s Range of Light.
• Morey, Kathy and Mike White, Sierra South, Backcountry Trips in California’s Sierra Nevada.
• Wiese, Karen, Sierra Nevada Wildflowers.
• Laws, John Muir, The Laws Field Guide to the Sierra Nevada, California Academy of Sciences.

Conservation

Today new forces are shaping the Sierra with human activity being one of the leading causes of change in weather patterns. Even the most remote lakes in the High Sierra show noticeable impact caused by fishermen’s trails and careless campers. Sierra Club has taken a leading role in raising awareness about the damages caused to the High Sierra ecosystem by frequent visitation and overuse. We will devote time during our trip to discuss the delicate balancing act between preserving the wilderness and providing access to the natural treasures of the John Muir Wilderness.

Sierra Club National Outings is an equal-opportunity provider and when applicable will operate under permits obtained from U.S. federal land agencies.