gistfile1.js

var map = new OpenLayers.Map({
    div: "map",
    layers: [
        new OpenLayers.Layer.Vector("GeoJSON", {
            strategies: [new OpenLayers.Strategy.Fixed()],
            protocol: new OpenLayers.Protocol.HTTP({
                url: "county_file.json",
                format: new OpenLayers.Format.GeoJSON({})
            })
        })
    ],
    center: new OpenLayers.LonLat(-74, 42),
    zoom: 11
});