Grass Wren
Cistothorus platensis
The grass wren is 10 to 10.5 cm (3.9 to 4.1 in) long. Its upperparts are buffy brown with black and buffy whitish streaks on the back. The wings and tail have dusky bands. Its underparts are mostly buffy. Voice: The grass wren's song is a "series of short,...high notes such as high rattles, sharp trills, sparrowlike 'tr-tr-tr-tr' and nasal 'zèzèzèzè'."
ID text from Wikipedia, CC BY-SA 4.0
Rock Wren
Salpinctes obsoletus
The rock wren is between 12.5–15 cm (4.9–5.9 in) in length and has a wingspan of 22–24 cm (8.7–9.4 in). It has a bill length of 18.7 mm (0.74 in) in males and 17.8 mm (0.70 in) in females. Its wing length is 70.3 mm (2.77 in) in males, and slightly less at 67.8 mm (2.67 in) in females; similarly, its tail length is 51.9 mm (2.04 in) and 47.8 mm (1.88 in) in males and females, respectively. However, males weigh 15.7 g (0.55 oz), slightly less than females, who weigh 17.2 g (0.61 oz). Voice: Female rock wrens do not sing; however, males have large repertoires of 69–119 syllables, each song a 1–2.5 second trill of repeated syllables, with 3–5 seconds between songs.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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