Sierra is a 1974 television crime drama series focusing on the efforts of National Park Service rangers to enforce federal law and to effect wilderness rescues.

The tenth episode, "The Urban Rangers", established that the park also existed within the same fictional world populated by the characters of Emergency!, its sister Mark VII show.

The two paramedic characters from Emergency!,[3] played by Kevin Tighe and Randolph Mantooth, also appeared in Sierra "The Urban Rangers".

Like many Mark VII Limited television dramas, the show centered on a pair of leads in a public service job, backed up by a supporting cast of characters from within the same organization.

The series finale aired on Christmas Eve as a modified version of its previously-unaired pilot episode, The Rangers.