How We Graze to Protect the Prairie

Southwest Washington's grasslands don't necessarily announce themselves. Drive past the ranch on Old Highway 99 and you'll see open pasture and some cows. Look closer, and a whole world hides in the grass.

When Ignatius Colvin arrived here in 1849, he found native prairie with grass as high as a horse's belly. Those prairies once covered more than 180,000 acres of Southwest Washington. Today, less than 3% remain. Some of what's left is here on the ranch, and keeping it here shapes almost every decision we make about where, when, and how long our cattle graze.

Why these prairies matter

The South Sound prairies hold some of the rarest habitat in the state. Camas, golden paintbrush, the Taylor's checkerspot and Mardon skipper butterflies, and the endangered Mazama pocket gopher all depend on them. These prairies also filter water into the aquifers we drink from, store carbon in their soils, and give us open space and dark night skies. Many are working lands, too, raising food and supporting local families.

The only reason these prairies still exist is because they’ve been managed by people for thousands of years. The First Peoples of this region burned the prairies to keep Douglas fir and overgrown grass from taking over, and native plants evolved with that disturbance. Left alone, prairie turns into forest or a thicket of Scotch broom. Grazing, done carefully, is one of the ways to keep it open.

What the conservation easement means

In 2005, Colvin Ranch became the first ranch in Washington to enroll in the NRCS Grassland Reserve Program. Most of the ranch is now under a permanent conservation easement. The native prairie can't be developed, and the land stays in agriculture for good.

The easement isn't a set of rules we follow once and forget. We build a grazing plan with our partners at NRCS and adjust it every year based on the weather, how plant populations are doing, and what the land is telling us. Flexibility is key because if you manage the same ground the same way for decades,  it drifts somewhere you didn't intend.

How we graze

The short version is that we utilize rotational grazing. Cattle are moved into a pasture, graze it, then are moved out before it's overgrazed. Then we bring them back once it has regrown. In practice, it comes down to a handful of habits.

• Leave four inches. "We try to graze down to no shorter than four inches of stubble," says Livestock and Grazing Manager Jon Irvine. The goal is to use as much grass as we can to keep the cattle in good condition, while leaving enough for it to regrow.
• Small sections, frequent moves. Portable electric fence splits larger pastures into smaller sections, and the herd moves to fresh grass every couple of days during the spring and summer growing season. The cattle graze more evenly instead of picking their favorite plants, and each section gets time to rest.
• Step aside for the camas. In spring, we keep cattle off native prairie while camas and other native flowers bloom and set seed. Afterward, the cattle come back to knock down competing grass and leave behind natural fertilizer, giving those seeds room to take hold.
• Let the grass set the schedule. These pastures aren't irrigated, so most get one grazing in spring and one in summer. Some hold water better and grow three times as much as others. A rainy summer can mean another pass in October. A dry one means no extra pass at all.
• Bank some for spring. When fall rain greens things back up, the question is whether to graze that regrowth or let it grow so it's ready for spring. A lot of this is judgment: walking out, looking at the grass, and deciding whether it's ready or whether it's time to move the herd.

What we don't do

"Our cows don’t necessarily bring back the native grasslands,” says Jon, “but our management doesn't damage it. By not fertilizing, not planting, the natural grasses come back."

And that's the heart of it. We don't fertilize, irrigate, or generally reseed the native prairie with pasture grasses (though we do have some NRCS projects coming up where reseeding some native prairie plants will help us establish a silvopasture). Introduced grasses like orchard grass don't do as well without that help, so conditions tilt toward the native plants that belong on this ground. The cattle are the tool. How we use them is what matters.

For weeds, we hand-pull tansy and thistle, mow brush, and spot-spray invasives like Scotch broom and Himalayan blackberry that the cattle won't eat. We don't broadcast spray in fields where cattle graze.

When the grass stops growing

By late fall, the pastures have given what they can. The herd comes off and moves to hay and alfalfa, and the prairie rests until spring. Cattle eat roughly 2 to 3% of their body weight every day, and more in cold weather, since eating is how they stay warm. Winter feed is alfalfa, grass hay, and oat hay, so the herd stays on forage year-round.

After 20 years under the easement, the results are easy to see.

• Plant diversity on the prairie is up 20% over the past 10 years.
• More than 160 plant species grow here, including more than 28 that the endangered Taylor's checkerspot butterfly depends on.
• In a three-year study with WSU Extension and other partners, native species richness on grazed plots rose 35%, and forage production didn't drop.
• Golden paintbrush seeded in those study plots took hold, and the species was removed from the federal threatened list in 2023.
• Activity from the endangered Mazama pocket gopher has increased.
• Along Scatter Creek, we've planted 1,900 trees to reduce erosion.

Beyond our fences

The same approach now reaches past the ranch. Across the road, on land that was once part of the family's 1850s homestead, we graze the Washington Department of Fish and Wildlife's Violet Prairie Unit to help restore native prairie on public land.

We’ve also taken on a five-year restoration project on the prairie next to the ranch. Scotch broom had crowded out much of the open ground there, so we’ve been clearing it out to make room for native plants to come back.

Why the beef matters to the prairie

None of this works without a ranch that can pay its own way. We're only able to take on additional conservation projects above and beyond what's required by our conservation easement because we're able to have a sustainable business selling beef.

Every beef share and every package from the store keeps this prairie a working landscape: grazed with care, rested when it needs it, and home to plants and animals found in few other places.

If you've hiked a Thurston County prairie, watched the camas bloom, or cooked Colvin Ranch beef, you're already part of this story. You're a Grasslander. Learn more about America's grasslands, or stock your freezer with beef raised on this prairie.