OTMC.V · 2026-09-17 12:00:00

Oreterra Wraps up Phase 1 Drilling at Trek South with Visible Copper Minerals and Broad Intercepts of Porphyry-Style Alteration Above Postulated Intrusion; Planning for 2027 Phase 2 Underway, Assays Pending

Exploration Programs

Oreterra Wraps up Phase 1 Drilling at Trek

South with Visible Copper Minerals and Broad

Intercepts of Porphyry-Style Alteration Above

Postulated Intrusion; Planning for 2027 Phase

2 Underway, Assays Pending

Toronto, Ontario--(Newsfile Corp. - September 17, 2026) -

Oreterra Metals Corp. (TSXV: OTMC)

(OTCQB: OTMCF) (FSE: D4R0) (WKN: A421RQ)

Oreterra

" or the "

Company

") is pleased to report

that the Phase 1, first-ever drill program at its Trek South porphyry copper-gold prospect, strategically

located in B.C.'s Golden Triangle adjacent to the southeast of Teck-Newmont's Galore Creek joint

venture, has now concluded. 13 holes were drilled during the program, 11 on Trek South 'A' Zone and 2

on Trek South 'Toe' Zone (Figure 1), for a total of 4,500 metres. Assay results are anticipated later in the

fall and will be used to guide a Phase 2 program in planning for 2027.

An orderly camp demob is

underway ahead of deteriorating weather conditions with key camp infrastructure including tent pads,

materials and drill pads left in place to facilitate both an earlier start and lower costs for the 2027 field

season.

Program Highlights

(Refer to Figures 1 and 2, and Photos 1 to 3):

Multi-hundred metre porphyry-style alteration intercepts in central holes:

Central holes

TS26-06, TS26-09 and TS26-10 (Trek South 'A' Zone (Figure 1)) all delivered multi-hundred metre

intercepts of strong to intense porphyry-style alteration;

Copper minerals accompany the alteration:

Alteration in the above three holes is

accompanied by visually encouraging observations of copper minerals including one or several of

bornite ± chalcopyrite ± chalcocite ± malachite ± chrysocolla (see Photo 1) ranging from trace

amounts over down-hole widths spanning several hundred metres to locally appreciable amounts

over ten of metres;

Underlying source intrusion is zeroed-in and primed for drilling:

The above three holes are

believed to lie above an underlying source intrusion which will be a key target of the Phase 2

program in planning for 2027. The presence of bornite and intergrown chalcocite in the system is

highly suggestive of a high-temperature magmatic (i.e. porphyry) source at depth;

Abundant copper minerals at the new Trek South Zone 'C':

Field work on the east side of

Trek South glacier has identified a large new area of intensely altered boulders bearing some of

the most abundant visible copper mineralization seen on the property to date, now designated

'Trek South C Zone' (Photo 2).

Planning to drill this is in 2027 is underway;

Trek South target area increases in size:

Along with the Trek South 'B' Zone identified on the

southwest side of the glacier in August 2025, strong porphyry-style alteration often accompanied

by visible copper mineralization is now known to be present around almost the entire 1 km

perimeter of the Trek South glacial basin (Figure 2);

Trek South 'Toe' Zone first-ever drill intersections:

Drilling of two short holes on the Trek

South 'Toe' Zone, believed to represent an Eskay Creek / VMS style of mineralization, has

returned visually highly promising results including multi-metre intersections of strong chalcopyrite

mineralization (Figures 1, 2 and Photo 3). Assays of Toe Zone surface exposures have in the past

returned high-grade Cu, Au, Ag, Zn & Sb (antimony) values.

"Trek South continues to be exceptionally encouraging as a new, large-scale porphyry prospect," said

Kevin Keough, CEO. "The Phase 1 drill program has given us everything we expected to see, shy of the

actual location of a source intrusion, though we now have a very good sense as to where it may be. The

visually exciting alteration and mineralization observed in drilling at Trek South 'A' Zone (Photo 1) and

'Toe' Zone (Photo 3), coupled with the new prospecting results at the 'B' and 'C' Zones (Photo 2), have

provided the basis for advancing to Phase 2, and we're very much looking forward to a return to the

property next year, with camp infrastructure and drill pads remaining in place to facilitate this."

Figure 1: Trek South Phase 1 drill hole locations on satellite image