Background

Donna Lass was the daughter of James P. Lass (August 28, 1897 – March 30, 1973) and of Frances Mary (Kukar) Lass (November 24, 1900 – August 5, 1982). Her father had been a farmer in the area of Beresford, South Dakota

Beresford, South Dakota

Beresford is a city in Lincoln and Union counties in the U.S. state of South Dakota. The population was 2,005 as of the 2010 census. The southern two-thirds is part of the Sioux City, IA–NE–SD Metropolitan Statistical Area, while the northern one-third is part of the Sioux Falls...

, and she was a 1962 graduate of Beresford High School

Beresford High School

Beresford High School is the main secondary school for grades 9-12 located in Beresford, South Dakota. It is the only high school in the Beresford School District 61-2. The school colors are purple and white. The school mascot is the Watchdog...

. She moved to the area of South Lake Tahoe, California

South Lake Tahoe, California

South Lake Tahoe is the most populous city in El Dorado County, California, in the Sierra Nevada Mountains. The population was 21,403 at the 2010 census, down from 23,609 at the 2000 census...

 in May 1970.

Disappearance

Donna Lass worked as a nurse at the Sahara Tahoe resort casino in Stateline, Nevada

Stateline, Nevada

-Demographics:As of the census of 2000, there were 1,215 people, 510 households, and 245 families residing in the CDP. The population density was 1,803.3 people per square mile . There were 562 housing units at an average density of 834.1 per square mile...

. On September 6, 1970, she signed her last entry in her log book at 1:50 a.m. She was never seen leaving the Sahara, however her car was found at her apartment complex at Stateline. Lass, then 25, was never seen again.

The next day, Lass' landlord and employer both received calls from a man who told them that Lass was ill and had left because of a family emergency. The call proved to be a hoax.

A month later, a paste-up postcard was received by the San Francisco Chronicle

San Francisco Chronicle

thumb|right|upright|The Chronicle Building following the [[1906 San Francisco earthquake|1906 earthquake]] and fireThe San Francisco Chronicle is a newspaper serving primarily the San Francisco Bay Area of the U.S. state of California, but distributed throughout Northern and Central California,...

, hinting that Lass's disappearance was connected to the Zodiac Killer

Zodiac Killer

The Zodiac Killer was a serial killer who operated in Northern California in the late 1960s and early 1970s. The killer's identity remains unknown. The Zodiac murdered victims in Benicia, Vallejo, Lake Berryessa and San Francisco between December 1968 and October 1969. Four men and three women...

. Six months later, on March 22, 1971, another paste-up postcard

Postcard

A postcard or post card is a rectangular piece of thick paper or thin cardboard intended for writing and mailing without an envelope....

 was received by the San Francisco Chronicle, the San Francisco Examiner, and the San Francisco Times. No evidence was ever uncovered to connect Donna Lass's disappearance with the Zodiac Killer.