I had never heard of this place until I started seeing it on some of the lat/long websites that I go to for Nevada historical sites. It was located in the Grass Valley about four miles south of Walti Hot Springs/ Gund Ranch. The active Gund Ranch sits just inside of Eureka County. Hiller sat just inside of Lander County. I haven't been able to find much written information about this place. I found one obscure passage about it written in Nevada Places Names- A Geographical Dictionary by Helen Carlson. That passage reads: "A former post office of Lander County, active from August 14, 1919, until January 15, 1921, when Beowawe became the mail address for its patrons." Nevada Post Offices by James Gamett and Stanley Paher confirms that information. I wanted to know more, so I went to the newspaper archives. I didn't find much, but I did come up with a little information. Sam Hiller was a prominent rancher outside of Fallon. He is cited in a few newspaper articles leading up to 1919. On June 11, 1919, a Fallon newspaper reported: "Sam and Ed Hiller arrived in Fallon Monday evening from their ranches in Grass Valley, Lander County, where they have taken claims and believe they have an excellent prospect of realizing handsomely upon their pioneering. They will be here several days attending to business matters." On September 20, 1919, the Eureka Sentinel reported: "The charge of issuing a false check made against Edward Hiller of Grass Valley, Lander County, by Tony Siri of Palisade, has been dismissed. It was found that the neglect of Hiller's brother to make a deposit in the bank as had been arranged for brought on the trouble, and has now been satisfactorily settled. The case has been dismissed by the Justice Court at Palisade." It isn't much, but it's more than I knew a few days ago.
Post Office: See above.
Last Trip/ Road Conditions: The Grass Valley Road is 103 miles from I-80 to Highway 50. Hiller sits out towards the center. The road is dirt, but it is wide and graded. Weather changes roads in Northern Nevada though.
Sources: Nevada Place Names- A Geographical Dictionary (By: Helen S. Carlson); Nevada Post Offices- An Illustrated History (By: James Gamett & Stanley W. Paher); Churchill County Standard (Newspaper); Eureka Sentinel (Newspaper).