Red twinberry is a shrub with a number of stems from 1-2 meters high. The short-petiolate leaves are elliptic, ovate or oblong in shape with subcordate bases and obtuse to rounded tips. They range from 2-8 cm and 1-4 cm wide. The upper leaf surface is glabrous with the lower surface glabrous to covered with coarse or stiff hairs.

The white to whitish-yellow flowers are in pairs at the ends of the stems. The flowers are pendent and are narrow at their base and flair outwards at their openings (funnel-shaped). The base of the tube is slightly spurred. Individual flowers range from 1-2 cm in length and are slightly two-lipped, the lobes of the corolla being slightly unequal in size. The fruit are bright red berries about 1 cm thick.

Red twinberry is found on moist open to wooded slopes from moderate to high elevations in the mountains.

Red twinberry may be found from southern British Columbia south to northern California and east to Alberta and hence south to Montana, Wyoming and Utah. It is absent from the Coast Range of Oregon.

In the Columbia River Gorge it may be found at approximately 4100' near the summit of Big Huckleberry Mt.