The earliest the author has found him to date in the Death Valley region was December, 1904. Book G, Inyo County Book of Mines, pages 525 and 526 shows Simpson and others forming the Gold Belt Mining District, on December 21, 1904. The Gold Belt district covered much of northern Death Valley and the ranges on both sides, the southern boundary spanning from Towne’s Pass in the Panamint Range to Daylight Pass separating the Funeral Range from the Grapevine Range. On December 22, the organizers of the district held a meeting at a place called "Simpson’s Springs," no doubt associated with Joe Simpson. Meeting attendants besides Joe Simpson were: A.V. Carpenter, W.L. McGregor, George E. Page, G.A. Fattler, Thomas King, Fred Adam, J.L. Starbrough, William Miller.
In January 1905, in Book H of the Inyo County Book of Mines, there is an entry in which Frank "Shorty" Harris and Joe Simpson located a claim in the Chloride Cliff area, across Death Valley in the Funeral Range, near the Keane Wonder mine and mill.
Simpson’s name in the Inyo County press began to show by early summer of 1906. In the June 6, 1906 Inyo Independent (Independence, CA) is found this article pinpointing Simpson at the new camp of Harrisburg:
"A.V. Carpenter and J.L. Simpson, mining men from Harrisburg, arrived in Independence Wednesday morning. They report the southern end of the county as being very lively, and mining property of merit being eagerly sought after."
Harrisburg, and by this time Skidoo, were turning the region’s and the nation’s newspapers attention to the western Death Valley country. Joe Simpson apparently had been in the district long enough that a month prior to this newspaper clipping, Joe Simpson became involved in a mining dispute over several claims in the area that became Skidoo, a dispute that eventually went to trial. He was wrapped up with this trial and subsequent appeals for the rest of his life.
"In the Superior Court of The State of California in and for the County of Inyo Jack Byrne Plff on Tom Knight and Joe Simpson Defts. Complaint Filed May 8th 1906 J.E. Meroney Clerk $5.00 pd Geo. Eagan Jackson Attorney for Plaintiff." — Superior Court of Inyo County (a handwritten note)
Jack Byrne was a Goldfield businessman who had grubstaked Tom Knight to locate ore bearing property in the Panamint Range. Somewhere along the line Knight drafted Joe Simpson to aid in his search. What transpired was that one or both of them located several mines that proved very rich right or very near the point of the expiration of the terms of the grubstake, which made Byrne mad enough to try to grab what he thought was his share.
"Notice of Protest — To whom it may concern: I, the undersigned claim an undivided one-half interest in the following described mining location viz: The Last Hike, Venus and Mars, groups of claims located by Tom Knight, and situated in the Wild Rose mining district, Inyo County, California. Jack Byrne." — June 22, 1906 Inyo Independent
"That on or about the third day of January A.D. 1906, at the Town of Harrisburg, County of Inyo, State of California, the said Plaintiff and the said Defendant Tom Knight entered into an agreement and formed a partnership for the purpose of prospecting for, discovering, locating, and developing and thereby possessing, holding and owning veins, lodes, ledges, mines and mining claims upon public mineral lands in the United States of America, and in and about the ‘Wild Rose Mining District’, County of Inyo, State of California." — Sworn statement, Superior Court of Inyo County
Jack Byrne and Tom Knight entered into an agreement effective between January 3 and April 26, 1906 that Byrne would supply Knight all supplies and food needed for a prospecting trip, in return for undivided one-half interest in any claims found. At some point Knight located 48 claims in the Last Hike group, eight claims in the Mars group, eight claims in the Venus group and four Jupiter claims; all located in the vicinity of Skidoo, given directions being 3 miles south of Emigrant Springs and 4 miles north of Harrisburg.