Aggregate

Roadway aggregate in Larimer County

Why Aggregate Matters

Larimer County maintains more than 400 miles of non-paved County roads, with over 200 miles located in the western third of the County. These roads serve as vital connections for rural residents, emergency responders, local businesses, and recreators. 

Maintaining safe, dependable access across the County requires a reliable supply of gravel aggregate to repair rutting, mud, wash boarding, and normal wear and tear. 

Safe, Reliable Access: New gravel is added periodically to keep non-paved roads smooth, stable, and passable, ensuring you can reliably reach your home, business and recreation spots. Gravel, like any other surface material, has a limited lifespan and needs to be replaced periodically. 

Emergency Response & Disaster Recovery: Dependable road surfaces allow emergency vehicles to reach rural and mountain communities without delay. Staging gravel locally also allows County crews to rapidly repair roads after natural disasters. 

Proactive Strategy to Source Aggregate: Rather than hauling gravel over 50 miles from a single Front Range gravel source, Larimer County is working toward establishing small, geographically dispersed gravel aggregate sources closer to the roads needing maintenance. This strategy reduces heavy truck traffic across the County, lowering carbon emissions and saving taxpayers’ dollars by reducing hauling costs. 

 

Gravel placing

 

Explore Our Aggregate Program:

Current gravel sources

Describes Larimer County's current process gravel sources.

Planning for future aggregate supply

Short-term options for replacing current gravel sources.

Current activities to secure more aggregate
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Aggregate is crushed rock, gravel, or sand mined from quarries and pits. You might hear it called “gravel” or “base course.”  While aggregate is used in concrete and asphalt roads, the focus of this site is aggregate used specifically to maintain non-paved roads in Larimer County. Aggregate is necessary for building and maintaining roads:  

Shouldering

  • Concrete roads: Gravel aggregate is mixed with cement and water to create strong, paved surfaces.  

  • Asphalt roads: Gravel aggregate is mixed with liquid asphalt to create a durable, flexible road surface 

  • Under concrete and asphalt pavement: Gravel aggregate is spread as a stable base layer to prevent cracking and shifting.  

  • Non-paved roads: Gravel aggregate is used as a surface layer to make them stronger, more durable, and weather-resistant.  

Without a periodic fresh layer of gravel aggregate, unpaved roads can deteriorate into mud or deep ruts during rain or snowmelt, making travel unsafe or impossible. Proper gravel surfacing keeps the roadbed firm, weather-resistant, and durable.

 

Surfacing material has a limited lifespan and wears down under traffic and weather. To keep our non-paved network safe and drivable, Larimer County Road & Bridge performs continuous, year-round maintenance. 

  • Nearly 9 Miles of non-paved roads resurfaced with fresh gravel annually.
  • About 40,000 Tons of aggregate spread across County roads each year.
  • Over 3,000 Truckloads of material placed and compacted by County crews.

FAQs

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  1. Why not use Larimer County’s existing Strang Pit for all aggregate needs in the future?

    The Strang Pit is a vital aggregate resource for Front Range roads, but long-distance hauling of Front Range aggregate to Western Larimer County is inefficient, costly, and limits the lifespan of the Strang Pit. Developing small, geographically diverse quarries near the roads that need maintenance reduces costs, helps to extend the life of the Strang Pit, and limits the impacts of gravel production to the communities that directly benefit from road maintenance.

  2. Who is paying for this aggregate?

    Securing aggregate is funded through existing Larimer County Road & Bridge Department operating revenue. Funding sources for projects are tied to Road & Bridge operating revenues. No new taxes or increases in fees are associated with securing aggregate. 

  3. What type of permitting is required to build new aggregate projects?

    Before any quarrying can begin at a site, Larimer County must undergo a thorough review and permitting process with State and County agencies. New projects on federal land (such as US Forest Service land) require a thorough environmental impact assessments in accordance with the National Environmental Protection Act (NEPA). All projects also require a 110 Construction Material Limited Impact Operation Permit from the Colorado Division of Reclamation, Mining, and Safety. A Location and Extent review is also required by the Larimer County Planning Department. Additional permits and review procedures are also required by the Colorado Department of Public Health & Environment and Larimer County Planning. 

  4. What is the regulatory oversight on aggregate quarry projects?

    In addition to the thorough review and permitting process required prior any construction, quarry projects are overseen by multiple agencies during operation. Site activities are regulated by the Colorado Division of Reclamation, Mining & Safety (CDRMS), the U.S. Department of Labor's Mine Safety and Health Administration (MSHA), and the Colorado Department of Public Health & Environment.

    Colorado Division of Reclamation, Mining & Safety (CDRMS) ensures compliance with permit requirements, statutory standards and regulatory rules. Mine Safety & Health Administration (MSHA) regulates site activities and enforces safety and health rules for all mines in the United States.  Colorado Department of Public Health & Environment regulates stormwater discharge and dust emissions from the site.

  5. Who can I contact to ask a question or provide feedback?
QUESTIONS? COMMENTS? CONTACT US

ROAD & BRIDGE DEPARTMENT 

PHONE: (970) 498-6052
Email us