A trailer for use with off-road vehicles such as all-terrain vehicles and snowmobiles. The disclosed off-road trailer can be adjusted to accommodate different trailer beds and attachments that can be readily off loaded and can be compactly packaged for shipping and storage. Modules for different conditions (e.g., ground or snow surface) can be implemented for multi-season usage. The disclosed suspension assembly enhances performance and robustness while maintaining cost effectiveness. The utility of the disclosed off-road trailer may be enhanced by grab handles for manual maneuvering, a rear bumper, and an active tail light. The overall design of the off-road trailer enables towing cargo behind a snowmobile or off-road vehicle over rough terrain at higher rates of speed than conventional off-road towable trailers.