Mars missions to date have interrogated the planet at very large scales using orbital platforms or at very small scales intensively studying relatively small traverses of the landscape. Long-range surveys of in situ resources on the surface of Mars could be readily accomplished with a fleet of Tumbleweeds - inflatable or deployable-structure vehicles capable of using the readily available Martian wind to traverse the surface of Mars with minimal power, while optimizing their capabilities to perform a variety of measurements over relatively large areas. These low-cost vehicles fill the niche between orbital reconnaissance and landed rovers. Fleets of Tumbleweed vehicles could conduct long-range, randomized surveys with simple, low-cost instrumentation that is functionally equivalent to conventional coordinate grid sampling. These vehicles can be suitably instrumented for surface and near-surface sensing and analysis and released to roam for the duration of a season or longer. It is anticipated that within just a few years, instruments such as gas chromatograph mass spectrometers (GC-MS) and ground-penetrating radar (GPR) will be deployable on Tumbleweed vehicles. Different Tumbleweed configurations can provide the capability to operate in varying terrains and accommodate a wide range of instrument packages making them suitable for autonomous surveys for in situ natural resources. Tumbleweeds are lightweight and relatively inexpensive, making them very attractive for multiple deployments or piggybacking on larger missions.