Taproots gradually ramified distally. Stems spreading to suberect, 1.5-2 cm. Leaves: basal leaves withering at or soon after anthesis, sessile, blade narrowly oblanceolate, somewhat flattened, 1-2 cm, margins entire, apex obtuse; cauline leaves absent. Inflorescences racemose cymes, 2-3-flowered, sometimes with flowers borne singly; bracts 5, proximalmost 3 in whorl, distalmost 2 opposite, subtending 2d (and 3d) flowers, oblong to oblong-obovate, 3-5 mm, apex obtuse. Flowers pedicellate, disarticulate in fruit; sepals 3-4, white to pinkish, 8-12 mm, scarious at anthesis, margins entire, apex obtuse; petals 7-9, white to pinkish, oblanceloate, 8-12 mm; stamens 7-9; stigmas 4-6; pedicel 3-9 mm. Capsules 7-10 mm. Seeds 5-10, 1.5-2.5 mm, smooth.

Flowering summer. Open, south-facing slopes on gravelly clay limestone-derived substrates; of conservation concern; 2200 m; Nev.

Lewisia maguirei is known only from the Quinn Canyon Range, Nye County.