On the Western Slope of Colorado, variable climate and precipitation conditions are typical. Periods of drought—which may be defined by lack of water, high temperatures, low soil moisture, or other indicators—cause a range of impacts across sectors, including water, land, and fire management.The Western Slope’s Upper Colorado River Basin (UCRB) was one of the first pilot areas in which the National Integrated Drought Information System (NIDIS) implemented a drought early warning system (DEWS) in 2009. NIDIS presently supports eight regional DEWS; as of 2016, the UCRB DEWS has been incorporated into an expanded Intermountain West (IMW) DEWS. The selection of the UCRB for an initial DEWS reflects the regional importance of drought information for managing water supply for agriculture and other uses, and the need for effective decision support related to drought. Additionally, new drought information products were developed specifically for the UCRB DEWS, and a number of others have been created since 2009, adding to the preexisting toolkit for drought decision making.The various elements of the UCRB drought early warning system can be expected to be more or less suitable for the needs of different decision makers. As a result, the UCRB makes an ideal case study to examine the use of scientific information products and tools in which the broad decision context (managing drought) is defined, but information needs of current and prospective users vary. Thus decision makers will make varied choices about which of the available tools to use or not use, depending on the particular management and institutional context in which they work. This report investigates the factors that affect the choices of decision makers about whether and how to use particular information sources, products, and tools. The investigation focused on the following research questions:What decisions do managers make related to drought in the Upper Colorado region and particularly the Western Slope of Colorado? About which impacts of drought are they most concerned?What indicators and information products do decision makers rely on to manage for the impacts of drought in this region?How do decision makers find out about and choose between available drought information sources, products, and tools?What gaps (if any) do they perceive in currently available drought information and tools?Studies of decision support tools or information sources often concentrate on the known users of a given tool(s). Such an approach can yield useful information; it provides rich insight into the experiences of users and can suggest design modifications to make existing tools more effective. Yet it is not an effective approach to capture the perspectives and needs of prospective tool users or to investigate the factors that affect whether or not someone chooses to use tools in the first place. To overcome this challenge, in this study the author instead used a geographically based sampling strategy in which a range of natural resource managers from preidentified Federal management units and selected State agencies on the Western Slope were considered prospective users of tools. Prospective users were then asked to describe in an open-ended fashion what information and tools they do or do not use and why. This approach allowed for respondents to report both use and nonuse of tools, and thus the ability to identify factors that influence information and tool use choices by managers.