Monarch butterflies currently face many threats, including the loss of their breeding habitat due to the ongoing decline of native milkweeds, their required larval host plants. During the spring, summer, and fall, western monarchs (those that overwinter along the California coast) breed in the states west of the Rocky Mountains, including California, Nevada, Oregon, and Washington. Yet, very little is known about where and when monarchs breed in each of these states. The Xerces Society, with support from the Monarch Joint Venture, has prepared this short web-based survey to gather information about the location of milkweed stands in the western states that potentially serve as important monarch breeding areas. If you know where milkweed grows, we'd appreciate you completing the survey. To document the distribution of available monarch breeding habitat, it is not necessary to distinguish one milkweed species from another; it is still possible to complete the survey even if you do not know which milkweed species you have seen. However, to help you identify milkweeds in your region, we have created guides to the native milkweeds of Oregon, Washington, California, and Nevada. These guides can be accessed at http://www.xerces.org/milkweedsurvey. Additionally, you can send photos of unidentified milkweed species to Brianna Borders, Xerces' plant ecologist, at brianna@xerces.org. In your email, please include the approximate location of the plants and the date the photos were taken. Once you enter the survey, you will have the option of reporting up to three separate stands of milkweed. For the purposes of the survey, please consider any milkweed plants observed within a 1/4 mile of each other to be a single stand. If you have more than three milkweed stands to report, please visit the survey a second time. The survey will be accessible through 2013. You can revisit it as many times as you like, to report additional observations.