Short answer There was no fixed or uniform price. On the late‑19th‑century frontier, criminal defense fees were privately negotiated and varied with the seriousness of the charge, the standing of the lawyer, the amount of travel and preparation involved, and whether there would be separate trials for multiple defendants. Contemporary western “minimum fee schedules” adopted by local bar associations suggest that, circa 1880s–1890s, a privately retained lawyer’s fee for a felony murder case in a territorial district court commonly ran in the low hundreds of dollars at the bottom end and into the high hundreds or more for a capital case, plus expenses—roughly:

• non‑capital felony: about 500
• capital murder: about 1,000+ (more for prominent counsel)

For three defendants tried on the same facts, counsel often quoted a single lump sum somewhat higher than a one‑defendant fee, or charged per defendant at a discount. A prominent territorial politician‑lawyer like “Colonel” William Parker would likely have been at the upper end of local ranges.

To anchor those ranges in the period’s money values: 15,000–25–300–$500 fee represented many months of a cowhand’s pay.

What we can document from the period While Dakota‑Territory‑specific price lists are hard to find in print, western bar associations and city directories in the 1870s–1890s commonly published “minimum fee bills” that included criminal work. A few representative examples from roughly the right time and region (wording varies, but the brackets are typical):

• Texas (various local bar “fee bills” printed in newspapers in the 1880s): consultation 25–50–250–$1,000; plus per‑diem for days actually in court and travel expenses.
• Colorado and Montana (late‑1880s/1890s local bar schedules): misdemeanor 100; non‑capital felony 500; capital case 2,500; plus per‑diem in court and expenses.

Criminal cases were not billed on contingency; the ordinary arrangement was a lump‑sum retainer intended to cover preparation and a set number of trial days, with a stated per‑diem for additional court days and out‑of‑pocket expenses (witness travel, transcripts, telegrams, etc.). Well‑known lawyers in thinly populated territories often charged above the minimum schedules.

Court‑appointed counsel (if the defendants were indigent) Dakota Territory, like many states by the 1880s, allowed courts to appoint counsel for indigent defendants in serious felonies and to order the county to pay “reasonable compensation.” The amounts actually allowed by county commissioners in that era were typically modest—often just a fraction of what private clients paid (for example, tens of dollars per stage of the case, occasionally into the low hundreds in a capital trial), and sometimes nothing at all unless specifically authorized. If Parker was appointed rather than privately retained, the Pennington County commissioners’ minutes for 1885–1886 would show any claim he submitted and the amount allowed.

What this likely means for Rapid City, Dakota Territory, 1885

• If Parker was privately retained by the three cowboys, a historically plausible fee would have been on the order of several hundred dollars total (say 1,000, plus expenses), with the figure toward the higher end if the charge was capital murder, if there were multiple trial days, or if Parker’s reputation commanded a premium.
• If he was appointed to defend indigent prisoners, the county payment (if any) would probably have been far lower—on the order of tens to a few hundreds of dollars total.

How to find the exact figure for your case Because individual fee contracts were private, the most reliable ways to pin down Parker’s actual fee in that particular Rapid City case are:

• Pennington County Commissioners’ proceedings (1885–1886): look for claims allowed to “W. H. (or W. F.) Parker” for “defending prisoner” or similar.
• Pennington County District Court minute books and criminal case files: appointment orders sometimes direct the county to pay a specified amount.
• Local newspapers (Rapid City Journal; Black Hills Daily Times/Deadwood papers) around the trial dates: defenses in serious cases were often reported, and fundraising or subscription drives for defendants’ fees were sometimes mentioned.
• Parker’s personal or law‑office papers (if preserved) at the South Dakota State Archives (Pierre) or local historical societies; probate papers can also list receivables from clients.

Context for affordability A pooled fee of, say, $500 would have equaled roughly a year’s cash wages for a single cowhand; three “cowpokes” might have scraped it together collectively, through help from their outfit or by raising subscriptions among friends, but it would have been a substantial outlay—hence the common resort to appointed counsel when defendants had no means.

If you can share the defendants’ names or the exact case caption/date, local archival lookups may be able to surface the commissioners’ allowance or a newspaper notice of the fee in that specific matter.