What is a flagpole annexation?

A "flagpole" annexation uses a thin corridor to connect distant land to the city, like a flag on a pole. This setup could potentially create an isolated enclave, making it harder and more expensive for the City to provide services like police, fire, and road maintenance equally to all residents.

What is the "1/6 contiguity" rule?

Colorado law (C.R.S. § 31-12-104(1)(a)) requires that at least one-sixth (1/6) of the perimeter of the land proposed for annexation must be directly contiguous (touching) the existing city boundaries. This is meant to prevent disconnected or leapfrog annexations.

The developer requesting annexation of the Crowsnest property claimed compliance by annexing a narrow strip along Crowfoot Valley Road in four separate maps, arguing that this strip meets the 1/6 threshold when measured against the total perimeter of the proposed area. However, many residents and the Town of Parker argued this was a loophole: the "contiguity" is artificial and created solely by the flagpole corridor itself, not a meaningful shared boundary with the city core. Critics say it doesn't reflect true integration and allows remote land to be annexed without genuine connection, leading to the isolated "island" concerns. 

For the developer's explanation and maps showing their 1/6 contiguity claim, see the official Crowsnest Annexation Petition (filed January 9, 2026) on the City of Castle Pines website. (The claim appears in paragraph 3 on page 1: "Not less than one-sixth (1/6) of the perimeter of the Property is contiguous with the City’s current municipal boundaries." Annexation maps in Exhibit C illustrated the corridor.)

Leapfrog Annexation Process? What is that?

The 4-step leapfrog process (also called a serial flagpole annexation or leapfrog annexation) is a legal strategy used by developers to annex remote, non-contiguous land into a municipality under Colorado's Municipal Annexation Act of 1965 (C.R.S. § 31-12-101 et seq.). It is specifically designed to satisfy the 1/6 contiguity requirement (C.R.S. § 31-12-104(1)(a)) when the main body of land does not directly border the city.

For example, the applicant for the Crowsnest annexation used the leapfrog method, as described in their Petition and annexation maps. Here’s how the 4-step leapfrog process works:

Step 1: Annex a thin "flagpole" corridor first

The developer annexes a narrow strip of land (in this case, a portion of Crowfoot Valley Road right-of-way) that does directly touch the existing city boundary. This strip becomes the "pole."

Step 2: Repeat with additional corridor segments

Additional separate annexation petitions are filed to extend the corridor farther along the same road. Each new segment touches the previously annexed strip, creating a chain. (Crowsnest used four separate maps to build this chain.)

Step 3: Annex the main "flag" (the large remote parcel)

Once the corridor is long enough, the developer files a final petition to annex the main body of land (e.g. the ~749 acre Crowsnest site). The law only requires 1/6 of the total perimeter of the entire proposed area (corridor + main parcel) to be contiguous with the city. The developer claims the cumulative corridor meets this threshold.

Step 4: City approves the final annexation

For example, if the City Council finds the 1/6 contiguity requirement is met (even though the main parcel is miles away and only connected by the artificial corridor), the entire area—including the remote island—becomes part of the city in one final ordinance.

What happens if land initially zoned "commercial" becomes zoned "residential"?

Zoning which allows flexibility for commercial areas to convert to housing potentially adds more housing density and erases projected revenue through sales taxes. This rezoning can potentially change a positive revenue stream to a deficit, leaving taxpayers to cover higher service demands for a denser, less revenue-generating development.

What are the concerns for wildlife and open space?

Annexations can fragment critical wildlife corridors for elk, deer, and raptors, risking habitat loss. The Comprehensive Plan states that open space is a priority for preserving natural features and minimizing environmental impacts. 

How could annexation affect property values?

Annexation which focuses on high density building could devalue existing homes by flooding the market with denser "comps" and eroding our premium small-town appeal—buyers seeking open space and low traffic may look elsewhere, as warned in the 2025 Community Survey.

What about water?

Warer is a critical resource in our state. Petitions for annexation must include:

-- The property being successfully included into an existing water service area by developer petition.

-- Sufficient water rights being dedicated.

-- Payment of potentially massive inclusion fees, tap fees, and infrastructure costs.

-- Compliance with water authority rules and capacity evaluations.