NexGen Energy Ltd. announced commencement of field programs focused on detailed geotechnical site confirmation studies on the Project and regional exploration drilling at the 100% owned, Rook I property (the ‘Property’), in the Athabasca Basin, Saskatchewan. The Rook I property is host to numerous electromagnetic (‘EM’) conductors and structural corridors which have yet to be explored as the focus has been on the development of the Arrow Deposit over the last several years. Target high priority areas within a 10 km radius of Arrow including along the Patterson Lake Corridor which hosts the Arrow Deposit. Together with priority targets along the Derkson Corridor which is directly parallel and to the east of the Patterson Corridor that hosts the Arrow Deposit. Arrow 2.0 Target – exploring greater than 300 m below known mineralization at Arrow to test for a replication of Arrow at depth where high grade mineralization remains open. Camp East Target – testing strong geophysical targets along a northeast conductor coincident with a regional north-northeast trend from Camp East through South Arrow and Arrow. Derkson Corridor – Parallel conductor corridor adjacent to the east of the Patterson Lake conductor corridor with highly prospective geophysical targets with known uranium mineralization drilled in historical drilling northeast, off of the SW2 property. Derkson East Target – series of northeast-southwest trending conductors within a strong geophysical and geochemical footprint. Derkson West Target – similar conductor to Patterson Lake Corridor with northeast-southwest trending conductor along magnetic gradient. Also, strong geophysical and geochemical characteristics. All target areas exhibit similar geophysical characteristics to Arrow, including strong conductive signatures with numerous off-sets coincident with discrete gravity lows and steep magnetic gradients. Structural interpretations across the property suggests several EM conductors lie along significant rheological/lithological contrasts which have been interpreted to possess structural conditions favourable for localizing uranium mineralization. Additionally, analysis of previous drilling has also revealed several target areas contain prospective alteration and geochemical signatures indicative of uranium bearing systems. Arrow 2.0 – The Arrow Deposit is open and remains highly prospective at depth; integration of geophysics (Magnetic and 3D-ZTEM data) and structural interpretation indicate Arrow is hosted on the limb of a large-scale fold that extends to great depth, which suggests the conditions favourable for localizing uranium mineralization also continue to depth. Furthermore, drilling at Arrow shows uranium mineralization, brittle structures, and hydrothermal alteration continue below Arrow. Arrow 2.0 target is designed to be a significant step down-dip from Arrow at depth to test for the replication of high-grade mineralization. Camp East – Lies along a recently defined north-northeast mineralized trend that includes the Arrow and South Arrow Deposits. Camp East was initially targeted and drilled in 2016 and returned highly prospective alteration, structural disruption, and anomalous geochemistry; intersections of anomalous Boron – a primary pathfinder element – have higher concentrations than the Arrow Deposit. Targeting at Camp East is focused highly prospective geophysical areas where bends and off-sets in the conductor have been interpreted as having increased potential to localize uranium mineralization within the north-northeast mineralized trend from Camp East through South Arrow and Arrow. Derkson Corridor – Exploration will focus on two target areas on the Derkson Corridor; a parallel conductor to the southeast of the Patterson Lake Corridor (‘PLC’) that hosts the Arrow Deposit and several other zones of high-grade mineralization along trend. The first target area lies on a series of northeast-southwest trending conductors at the edge of a prominent magnetic domain that represents favourable structural conditions for brittle reactivation and focusing mineralizing fluids. The target area is along strike to the southwest of historic drill hole DER-04 that intersected 2.5 m of 0.24% U3O8; an indication of a uranium fertile trend. Previous drilling to the southwest of the first target area has revealed anomalous boron intersections of up to 424 ppm in drill hole RK-15-070. Drilling will target northeast of the boron anomaly at jogs in the conductor that have potential to localize hydrothermal fluids and uranium mineralization. The second Derkson target lies along a similar northeast-southwest trending conductor to the PLC. Drilling in this area will target zones of structural dilation along the conductor that are interpreted to represent favourable locations for localizing uranium mineralization. A prominent jog on the conductor where the conductive signal weakens along strike of anomalous geochemistry has been prioritized for early program drilling.