Understanding the benefits received from urban greenspace is critical for planning and decision-making. The benefits of parks can be challenging to measure and evaluate, which calls for the development of novel methods. Crowdsourced data from social media can provide a platform for measuring and understanding social values. However, such methods can have drawbacks, including representation bias, undirected content, and a lack of demographic data. We compare the amount and distribution of park benefits elicited from (1) tweets on Twitter about Prospect Park, Brooklyn, New York (n = 451) with park benefits derived from (2) broad (n = 288) and (3) directed (n = 39) questions on two semi-structured interview protocols for park users within Prospect Park. We applied combined deductive and inductive coding to all three datasets, drawing from the Millennium Ecosystem Assessment’s (MEA) cultural ecosystem services (CES) framework. All three methods elicited an overlapping set of CES, but only the Twitter dataset captured all 10 MEA-defined CES. All methods elicited social relations and recreation as commonly occurring, but only the directed question interview protocol was able to widely elicit spiritual values. We conclude this paper with a discussion of tradeoffs and triangulation opportunities when using Twitter data to measure CES and other urban park benefits.