Where to Buy ABC, Base, Fill and Rock in Cochise County

On most driveway, pad and drainage jobs in this county the rock costs more than the machine time. It also comes from a short list of places, because aggregate is heavy and nobody trucks it far if they can avoid it. This is a landowner's guide to what the materials are, how the yards sell them, how to estimate a quantity, and which pits exist between Willcox and Douglas.

What the names mean

The one distinction to understand before ordering is base against surface. The FHWA gravel roads guide puts it plainly: base gravel "will generally have larger top-sized stone and a very small percentage of clay or fine material", while a good gravel surface "needs gravel with sufficient fine material which has a plastic or binding characteristic." Clean rock drains. ABC binds. Order the wrong one and you have either a driveway that stays loose or a French drain that does not drain.

By the ton or by the yard

Yards sell by weight or by volume, and the quote will say which. Converting between them is where estimates go wrong, because loose rock in a truck is lighter per yard than the same rock compacted into a driveway.

The Washington State DOT publishes the figures behind the rule of thumb. For crushed surfacing base course it gives 2,950 lb per cubic yard loose in the truck (1.48 tons) and 3,700 lb per cubic yard compacted on the road (1.85 tons). Those are dry weights for a Washington material, not a test of a Willcox pit, but the ratio is the useful part: material measured in place weighs about a quarter more per yard than the same material measured in the truck. WSDOT also adds 10 percent for waste. Order on the generous side; a short load means a second delivery charge.

The quarter-mile driveway, worked out

A quarter mile is 1,320 feet. Take a 12-foot running width, a single lane with a little shoulder.

• Area: 1,320 ft × 12 ft = 15,840 sq ft.
• At 4 inches compacted (0.333 ft): 15,840 × 0.333 = 5,280 cu ft, or 5,280 ÷ 27 = 196 cubic yards in place. At 1.85 tons per compacted yard, about 362 tons. In loose truck yards (÷ 1.48), about 245 yards.
• At 6 inches compacted (0.5 ft): 15,840 × 0.5 = 7,920 cu ft = 293 cubic yards in place, or about 543 tons; about 367 loose yards.
• Add 10 percent for waste and you are ordering roughly 400 tons for a 4-inch base and 600 tons for 6 inches.

That is base only. It excludes fill for low spots, clean rock for culvert bedding and any decorative top, and it assumes a firm subgrade; the FHWA guide wants at least 6 inches in the first lift over fabric on soft ground. Our quarter-mile driveway post covers the design side. Divide tons by what the yard's truck carries for the number of loads, which is how delivery is usually priced. Ask the yard; we are not going to guess a truck size for you.

Delivery or pick-up

Pick-up with your own trailer makes sense for a few tons of decorative rock, not for a driveway; 400 tons is not a trailer job. Delivery raises the question of whether the yard's truck can reach where the rock needs to go. A loaded end-dump wants a firm, reasonably straight approach, turning room and nothing overhead. If the driveway is the thing you are building, the first loads get dumped at the road and pushed in by the machine. Describe the access, and expect to pay for a wasted trip if the driver cannot get in.

The alternative is to let the contractor grading the driveway supply the rock. They buy from the same pits, know which truck fits which road, and the material shows up when the machine does. Compare the two numbers rather than assuming one is cheaper.

The yards

These are the suppliers we could confirm from their own websites, the chamber directories or their Better Business Bureau profiles, with phone numbers as published there. We have not bought from all of them and this is not a ranking.

Haul distance is a real part of the delivered price, so start with the pit nearest the parcel and work outward: Willcox for the Sulphur Springs Valley, Benson for the San Pedro side, Sierra Vista for landscape material and Benson or Douglas for bulk base on the south end.

What we could not confirm

• Prices. None of these yards publish per-ton pricing we could cite, and rock prices move with fuel.
• Klump Materials' product range. The chamber listing confirms the business and the phone number and nothing else.
• Whether each Benson and Douglas yard delivers, or sells to the public rather than to contractors only. The BBB profiles do not say.
• Local unit weight. The 1.48 and 1.85 tons per yard are WSDOT's figures for crushed base in Washington. Cochise County pit material will be in the same neighbourhood, not identical; a yard with a scale can tell you what its ABC weighs per loose yard.
• A Bisbee yard. We found none with a website, chamber listing or BBB profile.

If you would rather hand the whole thing to someone who orders rock every week, tell us the parcel and the job and a licensed local contractor will call you to quote it, material included.