## Facts

- The Pulls sought to buy about one acre in Jefferson County, Colorado, to build a mountain cabin and relied on an old fence line with “No Trespassing” signs as the apparent boundary.
- They purchased from parties who in good faith claimed title to the land the Pulls believed they were buying.
- Before construction, the Pulls hired a licensed surveyor to stake the cabin site but did not request a boundary survey.
- In August 1953, the Pulls began building a substantial cabin with a concrete slab and foundation; it was substantially completed by fall 1953.
- During construction, Barnes and Moffat were present on several occasions and interacted cordially; neither side knew or suspected the cabin was being built on defendants’ land.
- After completion, Barnes sought a right-of-way through the area; after the Pulls refused, she obtained a survey showing the cabin sat entirely on land owned by Barnes and Moffat.
- Defendants then fenced the Pulls out of the cabin and surrounding land, until a preliminary injunction issued in the Pulls’ boundary and damages action.

## Issues

1. Whether equity may grant relief to an innocent builder who, under mutual mistake as to a boundary, erects a substantial permanent structure entirely on another’s land.
2. Whether the trial court erred by refusing to apply equitable encroachment principles and denying relief on the ground that the doctrine recognized in prior Colorado decisions was inapplicable.

## Decision

- The Colorado Supreme Court reversed the district court’s judgment denying equitable relief.
- The court held that the trial court erred in concluding it could not apply equitable principles to a good-faith, mutually mistaken boundary construction.
- The case was remanded for the district court to consider and fashion an appropriate equitable remedy consistent with hardship-balancing principles.

## Legal Principles

- Where a substantial, permanent improvement is placed on another’s land through an innocent, mutual mistake about boundary lines, a court of equity may grant relief rather than enforce strict legal title in a manner producing extreme hardship.
- Equitable relief in encroachment and boundary-mistake cases turns on balancing hardships, including whether removal or forfeiture would impose a burden grossly disproportionate to the titled owner’s harm.
- An owner who observes another’s substantial expenditures made in reliance on an apparent boundary, without objection and under mutual mistake, may be subject to equitable estoppel against asserting strict title to capture the improvement.
- On remand, the trial court may consider remedies such as compensation for the land under the structure, boundary adjustment, easements, or other equitable dispositions aimed at avoiding unjust enrichment and disproportionate hardship.

## Conclusion

Because the cabin was built in good faith under a mutual boundary mistake and strict enforcement of title could impose disproportionate hardship, the Colorado Supreme Court required the trial court to apply equitable hardship-balancing principles and reconsider relief on remand.


Pull v. Barnes, 350 P.2d 828 (Colo. 1960)