The Codell formation
Geology, footprint, and mineral-owner context for the Codell, drawn from public USGS and state survey sources. Resource figures describe the play as a whole and are not a per-acre value. Every figure on this page is an estimate subject to verification of your specific interest.
Last updated June 2026.
What is the Codell?
The Codell is a Late Cretaceous sandstone and siltstone bench in the Denver-Julesburg (DJ) Basin that sits directly below the Niobrara and is stimulated and produced together with it, so a single Weld County tract often pays from both. It is oil-weighted in the DJ Basin core.
The Codell is the bench that rides with the Niobrara across the DJ Basin. It is a Late Cretaceous sandstone and siltstone, part of the Carlile interval, that lies directly below the Niobrara chalks in the Denver-Julesburg Basin. Operators routinely complete and produce the Codell and the Niobrara together, which is why a single Weld County, Colorado tract often pays royalties from both intervals at once. The Codell is oil-weighted, mirroring the oil core of the DJ Basin that runs from Weld County north into Laramie County, Wyoming. For a mineral owner, a Codell royalty is rarely a standalone story; it is usually one half of a combined Niobrara-Codell income stream, valued on the standard income multiple applied to the checks your wells actually pay.
Codell geology
- Age and lithology
- Late Cretaceous (Carlile) sandstone and siltstone, a relatively thin but productive clastic bench. Source: USGS Denver Basin Province assessment and Colorado Geological Survey.
- Paired with the Niobrara
- The Codell sits directly below the Niobrara and is stimulated and produced together with it, so a single DJ Basin tract often produces from both benches.
- Where it produces
- The DJ Basin oil core: Weld County, Colorado at the center, extending north into Laramie County, Wyoming.
How much oil and gas the Codell holds
The Codell is assessed as part of the USGS Denver Basin Province work alongside the Niobrara Total Petroleum System, with undiscovered, technically recoverable oil and gas reported for the Cretaceous reservoirs of the basin. These are undiscovered play-wide estimates, not proven reserves and not a measure of any individual property.
Source: USGS Denver Basin Province (Niobrara Total Petroleum System) assessment; Colorado Geological Survey.
What the Codell means for your minerals
A resource estimate for a play is not the value of your acreage. Your mineral and royalty interest is valued on the income your wells actually pay, roughly 36 to 72 times your average monthly royalty check, the same as 3 to 6 times your annual royalty. Where you land in that band depends on your wells decline, the operator, your royalty rate, and any undeveloped drilling upside. For the full method and a free on-screen estimate, see what are my mineral rights worth.
The Codell is part of the DJ Basin. For the basin-wide value bands and the counties we buy in, see the DJ Basin page.
Codell questions
- What is the Codell formation?
- The Codell is a Late Cretaceous sandstone and siltstone bench in the DJ Basin that sits directly below the Niobrara. It is oil-weighted and is produced together with the Niobrara, mainly in Weld County, Colorado and into Laramie County, Wyoming.
- Why do my checks show both Codell and Niobrara?
- Because operators complete and produce the two intervals together. The Codell sits just below the Niobrara, so a single DJ Basin tract often pays royalties from both benches at the same time.
- How are Codell minerals valued?
- A Codell interest is valued on the income it pays, roughly 36 to 72 times your average monthly royalty check, usually as part of a combined Niobrara-Codell stream. USGS resource figures describe the whole play, not your property. This is an estimate, subject to verification, not an offer.
Sources
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