1. INTRODUCTION
2. DATA PROCESSING
2.1. Observations
2.2. All-Source Catalog
2.3. Photometry
2.4. Candidate Cool Dwarfs
3. SEARCH FOR PERIODICITIES
3.1. Synthetic Light Curves
3.2. Significance Cuts and Visual Vetting
4. A CATALOG OF PS1 ROTATING COOL DWARFS
4.1. Estimated Stellar Properties
4.2. Cross-Identifications
4.3. Contaminants
5. DISCUSSION
5.1. Characteristics of the Rotating Sample
5.2. Very Slow Rotators
5.3. Amplitude of Variability
5.4. Wavelength-Dependence of Variability Amplitude
5.5. X-ray Activity
6. CONCLUSIONS