Vines appear in late winter or early spring in response to increased rainfall, and can climb or scramble to a length of 6m.

Although leaf size is highly variable, coastal manroot tends to have larger leaves than other Marah species.

Vines emerge from a large, hard tuberous root which can reach several meters in length and weigh in excess of 100 kg.

Newly exposed tubers can be seen along roadcuts or eroded slopes and have a scaly, tan-colored surface.

[2] Coastal manroot grows most vigorously by streams or in washes but can also be successful in dryer areas, at elevations up to 1600 metres.

[citation needed] Marah oreganus was used by the Native Americans for various health problems.

The Chehalis people burned the root and mixed the resulting powder with bear grease to apply to scrofula sores.

The Coast Salish made a decoction to treat venereal disease, kidney trouble and scrofula sores.

Although data for this specific variety of wild cucumber is limited, case reports of ingestion of other species within the Cucurbitaceae family have been found to induce severe illness requiring intensive care support to treat dehydration from the profound gastrointestinal distress.