The Hassayampa Flood Safe (Walnut Grove Dam, 1890)

[VERIFIED] The Walnut Grove Dam on the Hassayampa River, at 34.1931, -112.5416, failed in the early hours of 22 February 1890, releasing on the order of four billion gallons and killing between 70 and 150 people. It destroyed Wickenburg, Seymour and Smith's Mills and remains among the worst disasters in Arizona history. [PRIMARY] It was covered contemporaneously by the Arizona Weekly Journal-Miner on 26 February, 5 March and 19 March 1890, and independently in later documentary accounts drawing on Sharlot Hall Museum holdings. [SECONDARY] The cache claim — a saloon safe carried off by the flood and never recovered — rests on later compilation accounts rather than on a period loss report. [UNKNOWN] The saloon's town has never been established, and the proprietor's name is unstable between "Browl" and "Bob Brow." [UNKNOWN] Location. We publish no search area for the safe. The open questions are named rather than smoothed over, and they are exactly what a reopening would have to answer.

Case overview: estimated value Saloon safe contents claimed — no inventory, appraisal, or insurance record located; current status unrecovered; era 1890.

Search area: None published for the safe. The dam site itself is a documented historic location, but no cache location is supported at any grade.

Best modern approach: Establish the saloon first, before any terrain work. The testable path is the 1890 Yavapai County assessment rolls and business licences for Seymour, Smith's Mills and Wickenburg, plus the Journal-Miner run for March 1890, to fix the proprietor's name and the town. Until the saloon is placed, flood-deposition modelling has no anchor and would produce a search area with nothing behind it.

Evidence and provenance: [VERIFIED] Walnut Grove Dam failure, 22 February 1890, at 34.1931, -112.5416 — dam approximately 110 ft high and 400 ft across the top; [VERIFIED] Between 70 and 150 dead; Wickenburg, Seymour and Smith's Mills destroyed; [PRIMARY] Arizona Weekly Journal-Miner coverage, 26 February, 5 March and 19 March 1890; [PRIMARY] Walnut Grove Water Storage Company records and Sharlot Hall Museum photographic holdings; [SECONDARY] The saloon-safe cache claim appears in later compilations, including Arizona Highways, "Legends of the Lost," November 1995; [UNKNOWN] Which town the saloon stood in has never been established; [CONTESTED] The proprietor's name is given as both "Browl" and "Bob Brow" across accounts.

Legal notes: The Hassayampa corridor below the dam site crosses a mixture of BLM land, Arizona State Trust land, and private property, and includes the Hassayampa River Preserve. State Trust land requires a permit for entry. Confirm ownership parcel by parcel before any field activity.

Source origin: the earliest traceable published account is Contemporary newspaper coverage (event); later compilation (cache claim) (1890) in Arizona Weekly Journal-Miner, 26 Feb / 5 Mar / 19 Mar 1890 (event). Independent corroboration: yes. Sources that restate one another count as one source, not several.

Why this case is worth researching: The Hassayampa Flood Safe (Walnut Grove Dam, 1890) pairs a documented historical event with an unrecovered-cache claim, which is what the PinPoint Treasure pipeline is built to test — cross-referencing archival sources, geology, mining records, and 1-meter LiDAR terrain where coverage exists. Every claim on this page carries an evidence grade, and grades are never raised to fill a gap.

Recommended workflow for the The Hassayampa Flood Safe (Walnut Grove Dam, 1890) case: (1) read the primary sources and establish which of them are independent of each other, (2) run the cipher engine on any coded material, (3) scan the highest-probability bounding box with LiDAR where coverage exists, (4) cross-check anomalies against NDVI vegetation stress and iron-oxide satellite signatures, and (5) confirm land status before any field work.