If you felt some shaking ... you're not going crazy. A 4.9 magnitude earthquake happened about seven miles northwest of Smiths Ferry on Monday.
The earthquake was recorded by USGS at around 10:25 a.m. MT. People are reporting online that they felt it in Boise, Hailey and McCall.

No injuries or building damage has been reported yet. USGS says the region this earthquake happened in are resistant to earthquake shaking.
Recent earthquakes in the area have caused secondary incidents like landslides, according to USGS, but there are no current reports of any additional incidents.
Most large earthquakes are followed by aftershocks, which are smaller than the main earthquake. A small fraction of aftershocks can be larger than the original quake, but that is not likely.
USGS shows a small aftershock happened around 20 minutes after the first. That earthquake measured at 2.7 magnitude.
The last earthquake felt in the Boise area was a 6.5 magnitude in 2020 that happened near Stanley. That earthquake was the second-largest in state history, followed by the 1983 Borah Peak quake, which registered as a 6.9 magnitude.