By 1981, Harry Jones was writing new westerns at a fair rate of knots. On 4 March, even before signing the contract for Pit Prop, which had recently been accepted for publication by John Hale, he submitted the manuscript for Mustang Valley. After the slight embarrassment of submitting his previous western with around 15,000 words too many, Jones’ accompanying letter he said that the new book was “As near 40,000 words as makes no difference” (which most likely meant 45,000 words).
Hale accepted the book and both parties signed the contract during April. Jones accepted a fee of £75 for one edition of not more than 1,500 hardback copies. Jones coincidentally submitted the marketing blurb to Hale on his wife’s 60th birthday, 7 June, 1981. The proofs were sent to Jones on 18 September and he returned them with corrections on 26 September. Mustang Valley was published on 21 January 1982.