Mr. Don Gray reports

ENDEAVOUR SILVER PROVIDES Q1 2024 CONSTRUCTION PROGRESS UPDATE ON TERRONERA; CONSTRUCTION PROGRESS REACHES 53% COMPLETION

Endeavour Silver Corp. has provided a Q1 2024 construction progress update for its Terronera project in Jalisco state, Mexico. A photo gallery presentation accompanies this news release and can be found on the company website at Terronera project. All dollar references in this news release are in United States dollars.

The Terronera project made significant progress in the first quarter, as concrete work was nearly complete on the Upper Plant platform and erection of structural steel advanced for areas including crushing, coarse-ore storage, grinding, flotation and thickening. Mechanical installation of major equipment continued to advance on schedule and the project remains on track for commissioning in Q4 2024.

"Site activities ramped up rapidly, as overall construction surpassed the halfway milestone," commented Don Gray, chief operating officer. "We've been very pleased with progress of structural steel erection and major equipment installation including the semi-autogenous grinding (SAG) and ball mills, apron feeders and flotation cells. Our procurement and materials management planning has been effective in keeping pace with site construction. We've been able to install many components upon immediate arrival to site, while making use of the limited laydown area. Underground mine development continues advancing very well, and we anticipate initial ore access in Q2. We are exceptionally pleased with the progress our Terronera team is making and remain committed to successfully completing and operating Endeavour's next core asset."

Q1 2024 construction and development highlights

As of March 31, 2024, site works and activities included:

• Safety -- A strong on-site safety focus has enabled a notable 60-per-cent reduction in the lost-time injury frequency rate since Q2 2023, during a substantial increase in the work force. Continuing initiatives such as mandatory certification for working-at-heights, frequent field audits and inspections, rescue-team training, and regular emergency drills continue.
• Progress -- Over all project progress reached 53-per-cent completion, with more than $158-million of the project's budget spent to date. Project commitments total $225-million which is 83 per cent of the $271-million capital budget.
• Engineering -- Efforts have been transitioning over to construction support. Detail design was completed for the tailing storage facility (TSF), portal 2 waste dump, and lower platform excavation.
• Mine development -- During the quarter, over 1,000 metres of underground mine development was completed, bringing the total to over 3,200 metres. Mine crews continue working in portal 1, 2 and 4 declines with excavations well advanced for the explosives magazines and the main pump-station sump system.
• Upper platform plant site -- Surface mill and infrastructure construction is 56 per cent complete and progressing on schedule. Concrete work is 83 per cent complete, and structural steel erection is 80 per cent complete.
  • Primary crusher -- Structural and mechanical construction was initiated on the conveyor and apron feeder support steel, and the apron feeder was placed in position.
  • Course ore stockpile and reclaim (COS) tunnel -- Two apron feeders were installed in the COS tunnel along with structural steel support, which opened the area to install the SAG feed conveyor.
  • Grinding -- All major SAG and ball mill components were assembled. The high-pressure hydraulic pump was used for mounting the main bearings (spherical roller bearings), and all four bearings were installed under vendor supervision. Structural steel and pump installations continued.
  • Flotation -- All flotation cell tanks were set in place and installation of the drive decks and structural steel installation continued. Several drive decks were assembled on the ground and lifted as complete units for each flotation cell tank. The regrind mill was set in place.
  • Tailing thickener -- The floor foundation and wall concrete were completed and erection of steel commenced together with the installation of the thickener tank floor.
• Lower facilities platform and TSF -- Excavation for the TSF embankment key trench was nearly 60 per cent complete, and the lower platform area was nearly 45 per cent complete, with the excavated material suitable to use in the TSF key trench and as embankment fill. Concrete work on the lower platform is anticipated to start in Q2.
• Procurement -- Bulk materials procurement purchase orders have been released and lead times are aligned with the current schedule. The procurement team has focused on critical path purchases, such as electrical components and transfer chutes, and reducing bulk material lead times to increase schedule float.
• On-site personnel -- The work force increased to 150 employees and over 400 contractor workers.
• Community relations -- Supporting the local municipality continues to be a major commitment. A new miner training program for local community members was established to provide training and employment. The company also sponsored English and computer skills for local communities.
• Environmental -- Environmental and social assessment initiatives continue according to schedule as outlined under the Equator Principal requirements for project loan financing.

Next steps and planning

The Terronera project is on track for commissioning in Q4 2024.

For Q2 2024, surface construction will continue focusing on mechanical installations and initial electrical work for the crushing, coarse-ore stockpile, grinding, flotation and tailing thickener areas. Excavation of the lower platform is anticipated to be complete in the coming months. Concrete work is expected to be initiated for the LNG and power generation and concentrate and tailing filtration. Concentrate and tailing filtration structural, mechanical, and electrical installations will commence in early Q3.

Mine development in portal 1, 2 and 4 declines will continue with first ore development anticipated in Q2. Initial long-hole mining is planned for Q3 followed by cut-and-fill mining; ore will be stockpiled for mill ramp-up. Development activities at La Luz are anticipated to begin in Q2 with portal construction and ramp advance to ore access anticipated in Q4. The critical path remains the TSF and lower platform construction and advancing underground mine, where development is meeting expectations.

About Endeavour Silver Corp.

Endeavour is a mid-tier precious metals company with a strong commitment to sustainable and responsible mining practices. With operations in Mexico and the development of the new cornerstone mine in Jalisco state, the company aims to contribute positively to the mining industry and the communities in which it operates. In addition, Endeavour has a portfolio of exploration projects in Mexico, Chile and the United States to facilitate its goal to become a premier senior silver producer.

We seek Safe Harbor.