When I rounded the corner and my left front tire immediately sunk into a snowdrift I knew it was going to be a long walk.

It’s not that I was stuck.

The drift didn’t block the entire road. I could back out and turn around and chock the tires and so be reasonably certain that when I returned, the rig would still be parked there and not upside down at the bottom of a ravine.

But my drive turned into a hike much sooner than I expected.

Such is the persistence of the snowpack in the Elkhorn Mountains this spring.

The road — and I am stretching the definition to its breaking point in describing it as such — is the one that climbs from Baker Valley to Marble Creek Pass. The Forest Service has branded it as Road 6510. You might employ more colorful language after negotiating its boulder patches and steep grades and sections that resemble a creek bed more than a route for vehicles.

(See “Why Build A Road There?” below for a history of the road.)

Marble Creek Pass, elevation 7,542 feet, is a prominent notch in the sedimentary wall of the Elkhorns. The pass is also the southern terminus of the Elkhorn Crest National Recreation Trail, the 24-mile path that spans the range to Anthony Lakes.

Besides being a portal for hikers, and a travel link between the Baker and Sumpter valleys (albeit an exceedingly slow link, as compared with paved Highway 7), Marble Creek Pass serves as a bellwether for summer’s progress.

The combination of its natural topography, and the artificial sort created when crews blasted the route for the road in the early 1960s, makes the pass an ideal place for wind-driven snow to accumulate to prodigious proportions.

The deepest drift tends to form where the road makes a sharp turn just below the summit, on the Baker side.

Based on conversations with a couple dozen people over the years, I know I’m not alone in looking habitually at the pass — it’s visible from much of Baker City — and wondering when the drift will recede enough that rigs, or at least pedestrians, can get by safely.

Typically this happens around the latter half of June (the Sumpter side, which is much more exposed to the sun, often is driveable a month earlier).

So far this hasn’t been a typical year.

Which is why I had to park more than two miles from the top — and, more vitally for the hiker, about 1,500 vertical feet below.

I have driven about that far on the road as early as the middle of April. Those years, obviously, had much shallower snowpacks and much balmier early springs.

I made the trip on Memorial Day, and fortunately the weather was glorious — an occasional benign cumulus, the temperature in the upper 60s.

The snow covering the road was soggy slush for the top inch or so but firm enough beneath that I strapped on snowshoes only for the last half mile or so, when the day’s warmth began to make the surface unpleasantly slippery.

When I reached the last switchback, less than an eighth of a mile from the top, I could see that I would be going no farther.

The snow, pitched at an intimidatingly steep angle, was an unbroken expanse. If you slipped it would be a very long and fast slide with nothing at the bottom but trees and rocks to break your fall — and quite likely your skull. It’s dangerous ground unless you have an ice axe, crampons and competence crossing such terrain. Having none of these, I swigged some water, took pictures and headed back down. Spared the lung-searing chore of climbing I looked around a bit rather than staring at my own boots, and noticed things I had missed — avalanche lilies painting yellow a bare patch between snowdrifts, for instance.

Another heat wave of the sort we had earlier this week could speed the process by a week or more, but I’d guess the road to the pass won’t open to vehicles much before Independence Day.

And it might well be later than that if June is unseasonably chilly.

WHY BUILD A ROAD THERE?

The Marble Pass Road was built as a haul route for trucks carrying limestone from a quarry at Baboon Creek, on the Sumpter side of the pass, to a lime-processing plant in Baker Valley near the intersection of Wingville Road and Highway 30, about five miles north of Baker City. There were two such quarries, the other being on the Baker side, along Marble Creek, hence the name of the pass.

The two quarries, owned by the Chemical Lime Co., produced an estimated $8 million in chemical-grade lime between 1957 and 1971. The Marble Creek quarry was the first to be mined. It closed in 1963 in part because the limestone deposit was cut by a different type of rock. Chemical Lime then opened the Baboon Creek quarry, which operated from 1963 until 1971, when both the quarry and the processing plant closed. Lower-grade lime from the processing plant is still piled at the site; the bright-white mounds are conspicuous even from the top of Elkhorn Peak, more than 5,500 feet above.

Both quarries tapped deposits of limestone formed from the remains of billions of shellfish that hardened into calcium carbonate at the bottom of a tropical sea about 250 million years ago. The deposits are the biggest in the Elkhorns but only of moderate size for Northeastern Oregon. There are massive outcroppings of limestone in parts of the Wallowa Mountains, including the imposing west face of the Matterhorn, and along the Burnt River, where Ash Grove Cement Co. mines limestone to produce portland cement.

The name “Marble” for the creek and the pass refer to the metamorphic form of limestone. Marble is created when limestone, a sedimentary rock, is subject to heat or pressure, or sometimes both, over millions of years. Some of the rock in the Marble Creek area isn’t a true marble, but rather a sort of intermediate stage between limestone and marble.

Mike Upmeyer of Baker City, who died in 2010, told the Herald in 1995 that he drove limestone trucks over the pass in 1970 and 1971. “We just locked up the trailer and let it slide,” he said, referring to places where the grade reaches 15 percent, more than twice as steep as Ladd Canyon on Interstate 84. One driver was killed in October 1968 when his truck plunged off the road.