A prominent landscape painter of late 19th and early 20th-century California, he specialized in panoramic desert and mountain landscapes using impressionist brushstrokes. His early works were tonalist in mood, and his later paintings were more decorative and light hearted. He was born in Baltimore, Maryland, and raised in Lanark, Illinois where he worked on a farm. In 1882, he moved to San Gabriel, California to join his rancher-brother who, married to the sister of artist Guy Rose, managed the extensive Rose ranch. Wachtel taught himself to play the violin and then, while working as a furniture store clerk, became first violinist of the Los Angeles Philharmonic Orchestra. He began sketching still lifes and saved enough money to study briefly at the Art Students League in New York with William Merritt Chase. However, he did not like the teaching methods, so he showed his work, much of it city street scenes, privately to Chase. He then went to London and enrolled at the Lambeth School. Returning to California, he combined his music with giving art lessons by setting up a studio in the back of his parent's home on Griffin Avenue in Los Angeles. In 1904, he married a student, Marion Kavanaugh, referred to Elmer by William Keith, and they first had a studio on Sichel Street and later in the Arroyo Seco of Pasadena. But they spent most of the twenty-five years of their marriage traveling around Southern California and the Southwest in a specially artist-equipped motor car. In Arizona, they painted Hopi Reservation scenes and desert landscapes, and they also painted in New Mexico. Elmer died suddenly in Guadalajara, Mexico on a sketching trip. He was a co-founder of the Los Angeles Art Association, and his works are held at the Laguna Museum of Art.