The field of ecology has undergone a molecular revolution, with researchers increasingly relying on DNA-based methods for organism detection. Unfortunately, these techniques often require expensive equipment, dedicated laboratory spaces, and specialized training in molecular and computational techniques; limitations effectively excluding field researchers, underfunded programs, and citizen scientists from contributing to cutting-edge science. It is for these reasons that we have designed a simplified, inexpensive method for field-based molecular organism detection – FINDeM (Field-deployable Isothermal Nucleotide-based Detection Method). In this approach, DNA is extracted using chemical cell lysis and a cellulose filter disc, followed by two body-heat inducible reactions – recombinase polymerase amplification and a CRISPR-cas12a fluorescent reporter assay – to amplify and detect target DNA, respectively. Here, we demonstrate FINDeM in detecting Batrachochytrium dendrobatidis, the causative agent of amphibian chytridiomycosis, and show that this approach can identify single-digit DNA copies from epidermal swabs in under one hour using low-cost supplies and field-friendly equipment.