The working window here is shorter than the calendar makes it look. Base and compaction work runs well from late spring through fall, and at altitude the ends of that window move in on you from both directions: frozen ground in the fall will not take a plate, and saturated ground during snowmelt will not either. Most of the questions below come in during that stretch, in roughly this order, from the week someone starts pricing a job to the afternoon the truck pulls out.

Telling the piles apart before anything is ordered

Drain Rock, #57 and Class 6: which of these moves water and which carries weight?

Washed stone with the fines taken out drains. Graded material with fines in it builds. Drain Rock, #57 Stone and #67 Stone are all clean, so water runs straight through them, which is why they go in French drains, drywells and behind retaining walls. Class 6 Road Base and Crusher Run carry stone dust and binding fines, which is what lets them lock up under a compactor and carry a load.

The check in your hand is quicker than the grading line. Grab a damp handful of each: clean washed stone falls out of your hand, material with fines holds its shape. The fines fill the gaps between the larger pieces, so the mass locks together under compaction and spreads a wheel load sideways, while clean stone leaves those gaps open so water moves through and it never truly compacts. Put a material with fines in a drain and it silts up. Put clean stone under a drive and it shifts underfoot forever.

I have a low spot to raise and a lawn to seed over the top of it. One soil or two?

Two, and swapping one for the other is one of the more expensive mistakes on the list. Fill Dirt is screened with minimal organic matter, which is exactly what you want when raising a grade, because there is nothing in it left to decompose and settle. Top Soil is a screened balance of sand, silt and clay for the upper few inches under seed or sod. Garden Soil is compost-enriched for raised beds and planters, which matters in the alkaline, low-organic ground common across the state. Fill the hole with dirt; finish the top with soil.

Front Range clay, fabric and a bed that keeps moving

What does expansive clay actually change about the material I pick?

Expansive clay across much of the state swells when it takes on water and shrinks when it dries, and that movement is what breaks surfaces laid straight onto it. So the base layer matters more than the surface stone, and getting water away from the base matters more than either. Add repeated freeze-thaw cycling, sometimes several cycles in one week at altitude, and any layer holding water becomes a layer that heaves. The practical result: build deeper than you would in stable soils, crown the surface, and give runoff a route away from the work.

Is geotextile fabric worth putting down under a base on clay, or is it money wasted?

It depends what is above it. Under decorative rock in a bed, fabric is worth having, since it slows stone from working down into soil and makes the bed easier to refresh. Under a compacted base on soft or wet subgrade, a geotextile stops the fines pumping down into the clay and is genuinely useful. Under a drive on firm ground, fabric is often skipped without consequence. What fabric does not do is replace depth: it is not a substitute for a proper base thickness. It is also not a catalogue item here, so if the site calls for it, source it from a local landscape supplier rather than adding it to this order.

My xeric bed washes downhill every monsoon season. What holds it in place?

Three things, in order. Edge it, so there is something physical at the low side. Break the water up before it gets there, because a sheet of runoff crossing a path takes the fines out first and leaves the coarse grit behind. Then size the stone to the water: bed cover and borders will sit still on a gentle grade, cobble holds a dry creek bed, and a bank or culvert outlet that scours after snowmelt wants RipRap placed in layers over fabric. Rounded stone rolls, angular stone keys together and stays.

How deep it goes under whatever will drive on it

Sedans park on it now, but a gravel truck will use it during the build. How deep does it go?

The load sets the order of magnitude and the clay decides the rest. A drive carrying cars and a half-ton pickup wants less compacted base than a lane a loaded truck, a trailer or an equipment pad uses, and ground that holds water or was cut and refilled wants more again. There is no published depth table on this site to hand you, so take the guidance on the product page as the starting point, and treat whatever figure you settle on as a compacted thickness with the sod and soft topsoil stripped out first. Frost runs about 30 to 36 inches through much of the state, so no realistic base reaches below it; the aim is to keep water out of the layer, not to out-dig the frost.

The pile left over at the end of the job

There is half a ton of Class 6 sitting in the corner of the yard. Keep it or lose it?

Base and crusher run, yes. There is always a soft spot by a gate, a rut at the end of a drive or a shed pad to thicken, and stockpiled base keeps indefinitely if it is not sitting in the runoff path. Decorative rock is worth keeping if you can cover it, since it is what you will want for a repair that matches. Soils and mulch are the exception: they break down, blow around and stop being what they were, so plan those closer to the quantity you need.

Once the material is settled, work the tonnage out in the material calculators, which also carry the unit question, the compaction allowance and the density behind each product. A narrow lane, what has to be ready on the day, and everything from the checkout screen to the tipped pile are on the delivery page.

Gravel Delivery FAQ: Ordering for Ground That Freezes and Swells