Contact or Visit Us
Quarry and Yard:
8200 Seven Locks Road
Bethesda, MD 20817
Driving Directions
Google Maps

By Mail:
P.O. Box 34300
Bethesda, MD 20827

Phone: 301-365-2100
Fax: 301-365-5524
Email: Information

Stone is a product of nature;
color, texture, streaking,
spotting, clefting, etc. varies.


Aggregates can be purchased in bulk by weight.
Fill up your truck bed, pick up 1.5 ton Super Saks, shovel 100 LB aggregate bags, or ask us to deliver these materials for you..
Aggregates cover 100 Sq. Ft. 2 " thick per ton.

Materials include:

2" Blue Gravel * 3/4" Blue Gravel
CR6 * Stone Dust * Concrete Sand * Masonry Sand * Pea Gravel * 1" Tan Gravel * 2" Tan Gravel Aggregate Pictures
Also See Decorative Landscaping Stones

We Deliver!

Pallet deliveries:
*$95 for the first two pallets
*$20 for each additional pallet
Limited delivery area.

Bulk deliveries:
*$20 per ton
Bulk deliveries include
aggregates, decorative stone and Carderock bulk veneer
Limited delivery area.

Mulch/Topsoil Deliveries::
*$95 for 5 to 15 yards
(5 yards minimum)
Local deliveries only.

Flagstone Deliveries:
Minimum 300 SQ FT
.30 per SQ FT.
Limited delivery area.

Driveway Waiver
Delivery Disclaimer

Building Materials
You will always find building materials in stock at Tri-State. We carry:

*Block*Rebar*Portland Cement*Brixment*Sakrete Concrete*Sakrete Mortar & Sand Mix*Angle Irons*Rebar
*Metal Lath*Wire Mesh* Galvanized Truss*

Dimensional Granite
We stock Granite in several forms, garden benches, curbing, pavers & veneer.Click here to see some examples of our Granite
Detergents, Sealers, Admixtures
We stock a wide variety of Detergents, Sealers and Admixtures. We carry detergents from Diedrich Technologies foundation coatings and concrete and masonry sealers by Thoro and Seaboard as well as concrete admixtures such as Sakrete accelerants

Carderock® Carderock can be purchased in bulk or on pallets. Options include:

* Premium Snapped Veneer
* Regular Snapped Veneer
* Bulk Veneer
* Regular Palletized Veneer
* Garden Wall
* Drywall
* Special Sawn (Ashlar Patter)
* Sawn back Thin Veneer and Corners
*Carderock Chips
*Tumbled Carderocks

Pictures of Carderock®
Dealers who Stock Carderock®
View our brochure
Carderock® Specifications

Flagstone SQ's and REC's
We carry random squares and rectangles. This product is sold by the SQ. FT.

SQ and REC Flagstone
Flagstone pattern Sheet
Typical Patio Layout Pattern

Coping, Treads, Sills, Hearths, Caps & Steps
Coping, Treads, Sills, Hearth, Caps & Steps are available in PA blue, Indiana Limestone and various other imported products. We keep a large stock of various sizes, and what we do not have in stock can be ordered and customized for your design requirements. Click here to see our product page


Building Stone/Veneer
In addition to Carderock® we also stock many options for building stone and veneers. This stone is delivered to our yard from all across the country. There are hundreds and hundreds of pallets and bulk material to choose from. Veneer is generally used for homes, large walls, entrance ways & piers. See some examples of building stones and veneers

In addition to Carderock® we also have several options in stock. Wallstones can be dry stacked or set with mortar. One pallet of wallstone will yield approximately 30 SQ FT of wall. Wallstone is most commonly used for retaining walls and garden walls. Check out our Wallstone page

Tri-State Stone & Building Supply, INC and Ben Porto & Son, LTD., has been family owned and operated since 1926. The quarries flagship product is Carderock® Stone.This beautiful building stone is a mica-schist, with horizontal and vertical cleavage making it easy to work into numerous installation styles.

News, Events & Links

Links to Other Helpful Sites
Quarry Pictures
See us on ARCAT.COM
Submit Your Project Photos Here
Customers Photo Page

Building Materials Specifications

Be sure to check back periodically
for updates and future events


Irregular Flagstone
We stock a wide variety of irregular flagstone and flagging. This material can be purchased by the ton on pallets. Check out the irregular flagstone page for pictures. Coverage for irregular flagstone is approximately 100 SQ FT per ton.

Landscape Boulders
We stock a wide variety of landscape boulders. With many sizes, shapes and colors to choose from, you will always find what you need to compliment you landscape design. Click Here for our Boulders Page

Tools & Supplies
In our store you will find all of the tools and accessories you need to complete your project. We have a wide variety of:

*Slickers*Jointers*Gloves*Line*Tie Wire
Nails*Safety Products*

Thin Veneers
Thin Veneer is a lightweight alternative to Full Veneer while still maintaining the natural stone look. We stock a wide variety of Thin Veneers in various styles, sizes and color combinations. Have a look at some examples of Thin Veneers.
For applications that require a stone larger than our irregular flagstone, steppers are an option. We carry various steppers.
Click here for examples of our stepper products

Hours of Operations
Monday - Friday 7:30AM to 4:00PM
Saturday 7:30 to 11:30AM

Download our Price list
Pallet Selection Release Form

Specialty Products
Tri-State makes every effort to keep a wide variety of specialty products imported from all over the world In Stock We can also accommodate Special Orders as well as Direct Shipments for large projects.

Special orders for Indiana Limestone and Pennsylvania Thermal Treads include:

*Custom sizes for treads
*Custom sizes for columns

Click here to see some examples of special order and specialty products.

**Please contact Brian Porto for more information on these products and for competitive quotes for special orders and direct shipments.***

As Seen in Stone World Magazine
Commercial Applications
Tri-State Stone and Building Supply has provided the finest Quality Carderock® Stone and specialty products for many commercial applications.
Residential Applications
Tri-State Stone & Building Supply provides materials for high end residential applications such as this cascading waterfall in Chesapeake, VA. Click here for an overview of the waterfall

Concrete Pavers
We sell Hanover® and Nicolock® concrete paver products. What we do not have in stock can be ordered and in most cases picked up or delivered on the next business day.

Hanover® Pavers
Hanover Price List

Nicolock® Pavers
Call 301-365-2100 for pricing

Landscape Products &
Decorative Landscape Stones

We carry a wide variety of landscape materials and decorative landscaping stones. Including:

*Bulk Mulch*Leafgro*Topsoil* Fill Dirt
*Typar Landscaping Fabric*
Decorative Stones such as *Mexican Beach Pebbles* Delaware River Stone*Wakefield Chips*Red Chip*
Click here to see examples

Granite Cobblestones
We stock three sizes of Granite Cobblestones. "4x4"x4", 5"x5"x9" & 4"x7"x10". These are sold by the ton but can also be purchased individually. Click here to view sizes