The　paper　presents　the　output　data-only　dynamic　testing　on　a　steel-girder　cable-stayed　bridge　over　the　Ohio　River　at　Maysville,　Kentucky,　USA.　The　bridge　has　a　total　length　of　2,100　ft.　with　the　cable-stayed　span　being　1,050　ft.　long.　The　field　dynamic　testing　was　carried　out　just　prior　to　opening　the　bridge　in　order　to　obtain　the　baseline　dynamic　characteristics　of　the　bridge.　Loaded　trucks　were　run　to　excite　dynamic　response　of　the　bridge.　The　acceleration　responses　of　80　deck　stations　were　recorded　as　trucks　drove　a　high-speed　pass　and　a　slower　bump-and-brake　pass.　Both　the　peak　picking　method　in　frequency　domain　and　the　stochastic　subspace　identification　method　in　time　domain　are　used　for　the　output　data-only　system　identification.　A　good　agreement　of　identified　frequencies　has　been　found　between　two　methods.　The　dynamic　test　results　will　be　used　to　establish　the　baseline　finite　element　model　that　reflects　the　built-up　structural　conditions　for　the　long-term　structural　evaluation,　damage　identification　and　health　monitoring　of　the　bridge.