Critical One Energy Drills 4.0 Meters of 70.2% Antimony at Howells Lake Project

Toronto, Ontario–(Newsfile Corp. – May 15, 2026) – Critical One Energy Inc. (CSE: CRTL) (OTCQB: MMTLF) (FSE: 4EF) (“Critical One” or the “Company“) is pleased to announce assay results from drilling at its flagship Howells Lake Antimony-Gold Project (“Howells Lake Project”) located approximately 120 kilometres west of the Ring of Fire access corridor in Ontario, Canada. Drilling intersected 4.0 metres (m) of massive stibnite grading 70.2% antimony (Sb) from drill hole HWL-2026-006 (“Hole 6”). The 4.0 m core length occurs within a broader 8.0 m interval grading 42.2% Sb. A second intercept of 7.3 m grading 1.62% Sb was also intersected. The 4.0 m of high-grade drill core approaches the chemical composition of pure stibnite, which is 71.7% Sb.

Highlights:

• Two mineralized zones were identified: 8.0 m of 42.2% Sb, including 4.0 m of 70.2% Sb in the form of massive stibnite, and a deeper zone with 7.3 m of 1.62% Sb.
• Near-pure stibnite: pure stibnite is 71.7 wt% Sb. The 4.0 m massive sulphide sits near that ceiling in modern drill core.
• Opens the opportunity for Direct Shipping Ore to North American military and industrial buyers, a supply route the West does not currently have.
• All eight holes drilled to date near the historic Howells Lake East Antimony Zone intersected visible antimony-bearing stibnite mineralization. Further assays will be released as they are received.

Figure 1. Close-up photos of interval 81 m to 85 m from Hole 6 that features massive antimony-bearing stibnite. Representative sample (A) shows a fractured cross-section of NQ drill core. Representative sample (B) shows outside of the split NQ drill core. Howells Lake Project, May 2026.

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Figure 2. Drill Hole 6 from 79 m to 87 m returned 42.2% antimony over 8 m of core length. Howells Lake Project, May 2026.

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Figure 3. Drill Hole 6 from 114.7 m to 122 m returned 1.62% antimony over 7.3 m of core length. Howells Lake Project, May 2026.

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“Hole 6 is the proof of concept we needed,” said Duane Parnham, Founder, Executive Chairman and CEO of Critical One. “It demonstrates that our Howells Lake Project has the grade and purity to be a strategically meaningful North American antimony source. In our view, the Howells Lake Project is proving itself to be one of the most impressive high-grade antimony deposits in North America, and this stands among the most significant Canadian mineral discoveries since Hemlo Gold, with more still to be uncovered.”

Parnham continued, “I also wish to extend our appreciation for the strong support of our valued partner, EFN, for the Howells Lake Project. Eabametoong First Nation’s spiritual guidance, commitment and partnership play a vital role in advancing this important initiative, and we are grateful for their continued backing and collaboration.”

Figure 4. Locations of drill collars at the Howells Lake Project. The alteration zone (green outline) is a trace to surface of historic and recently identified sericite-fuchsite alteration, which is associated with antimony-gold mineralization. Coordinates are in UTM zone 16.

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Table 1. Preliminary Results from HWL-2026-006

Note: Reported intervals represent drilled lengths; true widths have not been estimated due to insufficient geological information. Assays are pending from 122 m to the end of the hole at 306 m.

Drill Hole ID	From (m)	To (m)	Length (m)	Sb (%)
HWL-2026-006 (165°/-50°)	79.0	80.0	1.0	32.3
	80.0	81.0	1.0	4.6
	81.0	82.0	1.0	53.4
	82.0	83.0	1.0	74.3
	83.0	84.0	1.0	76.6
	84.0	85.0	1.0	76.6
	85.0	85.5	0.5	34.8
	85.5	86.0	0.5	2.1
	86.0	87.0	1.0	1.1
Composite	79.0	87.0	8.0	42.2
HWL-2026-006 (165°/-50°)	114.7	115.6	0.9	3.01
	115.6	116.2	0.6	0.50
	116.2	117.0	0.8	0.95
	117.0	118.0	1.0	1.41
	118.0	119.0	1.0	2.08
	119.0	120.0	1.0	1.82
	120.0	121.0	1.0	1.63
	121.0	122.0	1.0	1.15
Composite	114.7	122.0	7.3	1.62

Upcoming Live Webinar – May 19, 2026

Critical One will host a live investor webinar on Tuesday, May 19, 2026 at 1:00 p.m. Eastern Time, where management will discuss the significance of this discovery and take live questions.

Investors, analysts, brokers, media, and other participants are invited to attend the live webinar at the following registration link: https://my.demio.com/ref/CYETYZyNBbI04rkj.

A replay will be available to registered participants shortly following the live event.

QA/QC and Sampling Procedures

Samples of NQ diamond drill core were sawed at Critical One Energy’s operations base in Thunder Bay, Ontario. One-half of the core was retained for reference and one-half was added to sample bags in intervals no greater than 1.0 meter. Blanks of crushed pure-quartz aggregate, antimony-gold standards, and duplicates were inserted every 20 samples. Laboratory “Barren Wash” was completed during crushing and pulverizing, and additional blanks were inserted after visible high-grade antimony and/or visible gold. Samples, standards, and blanks were bagged, tagged, and delivered to AGAT Laboratories in Thunder Bay, Ontario where samples are crushed and prepared for analysis in Calgary, Alberta. Gold was analyzed by fire assay with ICP-OES finish on 50 g samples (202-552). Antimony and 30 additional elements were analyzed by sodium peroxide fusion and ICP-OES finish (201-079). Overlimit (>5% Sb) antimony analyses were reanalyzed by pressed-pellet wavelength-dispersive XRF (11321). Results above 5% Sb are reported as WDXRF and should be considered semi-quantitative data that will require confirmatory mineralogical and fully calibrated chemical analyses where definitive compositional determination is attained. Sulphur content can be reported low by XRF which can result in a high reporting of antimony. Comparison of methods used are found in Table 2. AGAT Laboratories holds key accreditations, including ISO/IEC 17025:2017, from the Standards Council of Canada (SCC), the Canadian Association for Laboratory Accreditation (CALA), ANSI National Accreditation Board (ANAB), and the American Association of Laboratory Accreditation (A2LA).

Table 2. Comparative analyses of Sb and S for overlimit Sb samples.

Drill Hole ID	From	To	Peroxide ICP-OES		XRF
			Sb	S	Sb	S
HWL-2026-006 (165°/-50°)	(m)	(m)	%	%	%	%
	79	80	7.33	7.22	32.3	12.7
	81	82	14.7	19	53.4	19.7
	82	83	18.1	30.1	74.3	25
	83	84	10.3	28.8	76.6	22.7
	84	85	9.28	29.7	76.6	23
	85	85.5	9.49	8.93	34.8	14.1

Qualified Person

The scientific and technical information in this news release has been reviewed, verified and approved by Matthew Trenkler, P. Geo., Chief Geological Officer of Critical One Energy Inc., a “Qualified Person”, as defined under National Instrument 43-101 Standards of Disclosure for Mineral Projects. Verification included a review of laboratory assay certificates, drill logs, chain-of-custody records, blank/standard/duplicate statistics, and review of collar and down-hole survey data. No QA/QC failures were identified.

About Critical One Energy Inc.

Critical One Energy Inc. is a Canadian critical minerals and upstream energy company focused on metals essential to energy, technology and national defence supply chains. The Company is advancing the Howells Lake Antimony-Gold Project, which provides Critical One with direct exposure to antimony, a critical mineral of increasing strategic importance to Western nations, as well as meaningful gold exploration potential across the property. Backed by seasoned management expertise, Critical One is positioned to advance high-value mineral projects aligned with the rising demand for secure critical minerals supply. The Company also holds uranium and copper assets in Namibia, providing additional exposure to critical minerals and energy metals.

Additional information about Critical One Energy Inc. can be found at criticaloneenergy.com and on the Company’s SEDAR+ profile at www.sedarplus.ca.

Neither the Canadian Securities Exchange nor CIRO accepts responsibility for the adequacy or accuracy of this release.

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