v3.25.4

Cover	Feb. 03, 2026
Document Type	8-K
Amendment Flag	false
Document Period End Date	Feb. 03, 2026
Entity File Number	001-41984
Entity Registrant Name	Black Hawk Acquisition Corporation
Entity Central Index Key	0002000775
Entity Tax Identification Number	00-0000000
Entity Incorporation, State or Country Code	E9
Entity Address, Address Line One	4125 Blackhawk Plaza Circle
Entity Address, Address Line Two	Suite 166
Entity Address, City or Town	Danville
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94506
City Area Code	(952)
Local Phone Number	217-4482
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Entity Emerging Growth Company	true
Elected Not To Use the Extended Transition Period	false
Units, each consisting of one ordinary share and one-fifth of one right
Title of 12(b) Security	Units, each consisting of one ordinary share and one-fifth of one right
Trading Symbol	BKHAU
Security Exchange Name	NASDAQ
Ordinary shares, par value $0.0001 per share
Title of 12(b) Security	Ordinary shares, par value $0.0001 per share
Trading Symbol	BKHA
Security Exchange Name	NASDAQ
Rights, each right entitling the holder to receive one ordinary share
Title of 12(b) Security	Rights, each right entitling the holder to receive one ordinary share
Trading Symbol	BKHAR
Security Exchange Name	NASDAQ

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For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Black Hawk Acquisition Corp 8-K