The Band-tailed Sierra-Finch is a slim finch with a long and conical yellow bill and bright yellow legs and feet. Males have a grey hood, slightly darker mask, and white underparts. Some forms are dark grayish on the back with darker streaking; others are brownish with darker streaking. The tail is unique, blackish-gray with a big bold white stripe created by white patches on the inner web of most of the tail feathers. Geographic variation is high, with six named subspecies which fall into two groups: a southern group and a northern group. The southern group is large and paler gray on the upperparts than the northern group; as well the division between the gray breast and white belly is less distinct than that of the northern group. Females are brownish and streaked, but show the distinctive white stripe on the tail, most easily seen from below. Males give their song from the ground or from and flight display. The song is a sneezy “tzii-chew,” sometimes repeated and geographically variable.