Snowmass Is Going Back Into Ziegler Reservoir. The Water Project Sets the Dig's Clock.

In the spring of 2027, Snowmass Water & Sanitation District crews will drain and deepen Ziegler Reservoir, the meadow lake where the 2010 "Snowmastodon" bones came out of the ground. The Denver Museum of Nature & Science will dig alongside them. The fossils will get the attention, but the water project is what sets the timetable. The district's August 2026 contractor briefing says construction can begin in early March and must finish by mid-September 2027. The science happens inside that window. In 2010 and 2011 that same kind of window held the museum to about a tenth of the reservoir floor.

A water project first

The district is deepening Ziegler to add 40 million gallons of raw-water storage. "Raw water reservoir storage is fundamental to our long-range planning goals," district manager Kit Hamby said in a release quoted by The Aspen Times. He called the added capacity "an indispensable asset during periods of drought and low stream flows."

The district's site-visit presentation from August 10, 2026 lists three program goals: more storage, better water quality and lower demand for snowmaking water. It also calls for a reinforced-concrete sidehill intake. The fossil dig comes along because the excavation is already happening.

Where 190,850 cubic yards of reservoir goes

This part of the project will show up on terrain that skiers and riders use. The district plans to excavate 190,850 cubic yards from the reservoir, then haul it, compact it and reseed it on Snowmass Ski Area. The presentation splits the material three ways:

• About 40,000 cubic yards go into the terrain park and bike park
• About 100,000 cubic yards are "mass placement"
• About 50,000 cubic yards are stockpiled as peat

The same presentation covers potential haul routes and ski-area disposal areas that were part of the bidders' tour. No trail or road closure schedule has been published yet. Anyone who rides the bike park or hikes near the village next summer should watch for one as the March start date gets closer.

The peat number matters for the science too. The district's site notes give Ziegler's history in layers. A moraine bowl about 35 feet deep formed during the Bull Lake glacial period, between 200,000 and 130,000 years ago. Glacial silt filled roughly the bottom 25 feet. Then a warm stretch between 130,000 and 20,000 years ago laid down a peat layer three to five feet thick. Those layers hold the record the museum wants to read.

The last two digs ran on borrowed time

The 2010 find was an accident. Aspen Daily News recounted that Gould Construction bulldozer operator Jesse Steele hit a mammoth bone with his blade. The museum sent a team, and the first dig became a race against heavy snow that lasted less than two weeks. In spring 2011, Hamby could give the museum seven weeks at most. In that time his crews had to dig out 80,000 cubic yards of soil, build a dam and refill the reservoir.

Even with those tight windows, the first two digs produced more than 6,000 large animal bones and 30,000 small animal bones. Snowmass Tourism's Ice Age page puts the mastodon count at more than 35 individuals. Aspen Daily News reports at least 50. It also notes the largest American mastodon from the site, nicknamed "Portaloo" because it turned up under the spot where the portable toilets had stood, the last area excavated.

The same report says only about 10 percent of the reservoir's footprint was excavated for fossils in 2010 and 2011. Most of Ziegler's floor has never been searched.

What the museum is after this time

Large predators top the wish list: a sabertooth cat, a short-faced bear, maybe a dire wolf. The bigger change is in the methods. Patrick O'Connor, the museum's director of earth and space sciences and senior curator, spoke at a September event in Snowmass:

"We now have more tools at our disposal to better understand the paleoenvironment in which these animals and plants lived, and how ecosystems responded during a period of intense change right here in Colorado."

The Aspen Times reported that the museum plans to analyze ancient soils, which may contain preserved proteins and environmental DNA. The aim is to piece together more precisely how plants, animals and climate changed together over tens of thousands of years. The soils left from the earlier digs may be as valuable as the bones.

Why a longer dig is harder to staff

A planned, months-long dig has its own logistics. Jacqueline Altreuter, the museum's vice president of strategic initiatives, told Aspen Daily News that the State of Colorado owns any bones found inside the reservoir's footprint, because the water district was formed by the state. The museum collects them under an agreement with the state and has to meet accreditation standards. That means volunteers need training and must commit for weeks or months, not single afternoons. She also described the work as physically grueling.

Housing is the other pressure. In 2011 the museum's team was given a bank of condos where they could sleep and plan each day. For 2027, Altreuter said, the team's housing needs will be larger because more people are staying longer and valley housing costs have climbed. "This is going to be a fundraising effort," she said.

The partnership so far includes the Aspen Science Center, Snowmass Tourism, the Town of Snowmass Village, the museum and the water district. Sara Stookey Sanchez of Snowmass Tourism and Alex Tarika, executive director of the Aspen Science Center, are working on volunteer coordination and public engagement. They said bringing back the community participation of 15 years ago is a priority, including the local teachers who dug next to museum staff. Sanchez also said the dig could bring visitors during slower weekday stretches and during the planned eight-month closure at Aspen/Pitkin County Airport.

Seeing Ziegler before the crews arrive

The land around the reservoir is private, so nobody can walk up to the shoreline. A free view is available from Spiral Point on the Rim Trail South, which the Ice Age Passport page describes as an overlook with viewfinders at the top. Aspen Daily News adds that you can also see the reservoir from the gondola, which costs money. Public tours and closer access for summer 2027 are still being planned.

Snowmass opens for skiing on November 26, 2026. For the winter, which it lists as running November 26, 2026, through April 11, 2027, Snowmass Tourism offers two ways to explore the story around the village:

1. A weekly guided Ice Age Explorer Tour. Check GoSnowmass for the winter day and time before you go.
2. The self-guided Ice Age Passport Walk. It's free. You collect clues and answer questions at the Tunnel Mural, the Tower Mural, the Skittles Gondola, Base Village Plaza and the Base Village Transit Center, then turn in a completed passport for a prize. The passport page lists the Town Hall front desk on weekdays as a year-round pickup point. Call ahead, because the page dates from 2023.

The museum is running staffing and volunteer coordination. As of September, volunteer spots had not opened to the public. Snowmass Tourism has an update list on the same page for news about the dig, visitor experiences and volunteering. If the volunteer requirements Altreuter described fit your schedule, sign up now so you hear when applications open.

Karina Kwasnicka Marx follows Snowmass Village through every season, and that includes a summer when the reservoir above town turns into a working dig site. If you'd like to talk about how 2027's construction and science calendar fits with your own plans for time in the village, let's connect and schedule a private consultation.