Could a Geothermal Plant Change Mount Princeton's Hot Springs? Here's Where Things Stand

On a November evening the pools below the Chalk Cliffs run until 9 p.m. at Mount Princeton Hot Springs. You can walk in without a reservation, and the soaking areas are open every day of the year. The heat in that water comes up through fractures and faults that run deep beneath Chalk Creek. A few miles north, near Maxwell Park and Rodeo Road, a local company has spent nearly two decades trying to tap the same underground heat to make electricity.

People in the valley have long wondered whether a power plant would turn down the springs. A peer-reviewed study published this spring gives the most detailed answer so far, and that answer depends on one variable nobody can measure yet. Measuring it takes test wells. Test wells need a lease, and the lease has been tied up since the summer of 2025.

What the model actually found

The paper ran in the journal Groundwater and was first published May 18, 2026. Its authors, Mickey Rush and Danny Birdsell of Neptune and Company, both live in Salida, according to The Mountain Mail. The resort asked for the research. The paper discloses that the work was done for the resort at counsel's direction, and it states that the funders had no role in the study design, the analysis, or the decision to submit it.

The study is a computer simulation. It couples groundwater flow with heat movement in a representative Upper Arkansas Valley system centered on Mount Princeton Hot Springs. It does not report measurements from an operating plant. The modeled project pairs an extraction well with an injection well, moves 1,500 gallons per minute, and puts every gallon back underground.

Here is the range of outcomes the scenarios produced at the springs:

Some scenarios cool the springs and others warm them, and that spread in the table is the main finding. In the low cases the pools lose heat and flow. In the high cases they run hotter and stronger than they do now.

Why the answer depends on placement

The same geology that feeds the springs is what makes them vulnerable. "Essentially, what we found was that the same plumbing that supports these hot springs can also provide a pathway for geothermal pumping to interfere with those hot springs," Rush told The Mountain Mail.

In the model, an extraction well drilled too close to the faults and shear zones that feed a spring could lower its temperature and flow at the surface. An injection well placed near those same structures could push more hot water upward. The researchers also said uncertainty is large. The work happens thousands of feet underground, the data mostly comes from geophysical surveys, and the exact effect of any one well can't be predicted without drilling it and watching how the springs respond.

The paper takes no position on whether a plant should be built. Rush said economists, politicians and community members "should have the ultimate say." The study names three things to monitor if a project goes ahead: water table levels in shallow aquifers, spring water temperature, and natural flow in the springs and nearby streams.

The developer agrees on one point. Hank Held of Mt. Princeton Geothermal LLC told a Salida Rotary audience that the size of the water pool a plant would draw from is a "big question mark" that will stay open until test wells are drilled, The Mountain Mail reported. So the study and the developer point to the same next step, and that step is the one that stalled.

How the parcel ended up in court

The site is state trust land managed by the Colorado State Land Board. The company has studied the resource beneath Maxwell Park since 2007, Ark Valley Voice reported. Its principals are Held and Fred Henderson, and the plan is a 10-megawatt plant. Held has estimated the build cost at $45,117,934, with the plant covering about 8.5 acres of a 3,900-acre lease. He has also floated using leftover heat for the Department of Corrections facility in Buena Vista and for up to 100 units of workforce housing.

Here is the order things happened in:

1. May 2024. The Colorado Energy Office awarded the company a $500,000 grant to research feasibility at Maxwell Park, matched by an investment from Western Geothermal.
2. June 2025. Partners Western Geothermal and Reykjavik Geothermal told Land Board staff they had divested less than 24 hours before the lease was due for review. Staff decided the company couldn't carry out the lease in time. The same month, staff denied a competing lease request from the company that operates Mount Princeton Hot Springs Resort. The Chaffee County Times described that request as an effort to block exploratory drilling.
3. June 30, 2025. The exploration lease expired.
4. August 14, 2025. The board voted unanimously to deny two requests: Mount Princeton Geothermal LLC's request to extend its expired lease, and a new exploration lease application from Princeton Holdings LLC. That left the parcel "unleased for geothermal exploration pending future Board approval of competitive process," according to the State Land Board's release.
5. September 17, 2025. The company sued in Denver District Court to get the lease back so exploratory drilling could start, Ark Valley Voice reported.
6. January 2026. Staff left Maxwell Park out of the state's statewide geothermal request for information because of the pending case. The board discussed the case in a closed session on January 21 and made no public statement, the High Country Advocate reported.
7. July to September 2026. The board's first geothermal request for proposals covered parcels in Alamosa, Rio Grande, Saguache, Las Animas and La Plata counties. None were in Chaffee County. Proposals were due September 20. The state's offering page now shows no bids on any of its 11 parcels.

Earlier coverage put the stall down to funding. The more recent reporting points to the lease. Held has said the next big hurdle is getting the lease back so confirmation drilling can prove the resource to investors, and the latest Mountain Mail coverage describes the project as stalled while it waits on a resolution with the state. A citizen group, Save Our Arkansas Valley, opposes the site and has urged the state to look at more remote locations.

What protects the springs if drilling ever starts

Held described the backstop this way to the Rotary audience:

"If Mount Princeton were to suddenly get a reduction of the temperature of water or amount of water, the State Land Board would shut us down. That's the safety net."

State rules add a layer that applies before any well is drilled. Colorado adopted deep-geothermal rules in August 2024. The Energy and Carbon Management Commission regulates deep operations, and the Division of Water Resources handles shallow operations and water use. HB25-1165, effective August 6, 2025, requires notice to operators of prior geothermal operations and gives them a chance to request a hearing if a proposed well might materially injure them. The Division of Water Resources counts certain historic public or commercial hot springs as prior geothermal operations. Registered operations get electronic notice of proposed water wells or deep-geothermal operations within a quarter mile.

That system gives a spring notice and a hearing. It does not set a fixed buffer around every spring. That fits the study, which found the risk depends on where a well sits relative to the faults, not simply on distance.

The next state milestone comes ten days after this post runs. SB26-142 directs the commission and the Colorado Geological Survey to gather geothermal resource data and send recommendations to the General Assembly by November 15, 2026.

This is general information about public rules and proceedings, not legal advice. Anyone with a water right or property question tied to geothermal activity should confirm the details with a qualified professional.

The water this winter

For now, the springs along Chalk Creek are running on their own. Mount Princeton keeps its 9 a.m. to 9 p.m. walk-in hours all year. Its locals club calendar runs into spring: 20% off private pool parties January 7 to 31, 2027, 20% off Wednesday lunch February 1 to 25, 10% off weekday spa treatments in March, and a $20 Monday burger-and-beer special in April. A Locals Punch Pass is required, and the lunch and burger offers are limited to Chaffee, Lake and Park County residents. The modeled range in the May study will stay a model until someone drills at Maxwell Park, and that can't happen until the lease question in Denver District Court is settled.

Questions about land near Chalk Creek, state trust parcels, or how a pending project like this might matter for a property you own come up often in this valley. Julie Kersting has followed the Maxwell Park story from the start and is glad to talk it through. Reach out to The Kersting Team at 8z Real Estate and Work With Julie.