Hi everyone,
I'm very local to this and wanted to join to share a few thoughts.
1) Trelewis is a village and Treharris is a small town, both former mining villages with the area Brooke was last seen in being reclaimed land from the old colliery. Both are very close-knit and neither are especially troubled with crime, which usually goes no further than the activities of bored teens.
2) The local rivers have been very swollen lately after weeks of heavy rain.
3) Going left from the lane Brooke was last seen walking down, the path is unlit but comes parallel to a lamppost-lit main road (B4255) after around 100 metres. After this, beyond the cenotaph, the path enters a much darker wooded area but it would have been almost impossible to reach the river from here due a long and heavily wooded bank. If she continued straight on the lane becomes Captains Hill, and this joins the B4254 a little further down. Captains Hill has streetlights, but they often seem not to be working. It's worth noting that even though both the B4254 and B4255 are main roads, they would have been very quiet at that hour. Had she turned right after walking down the lane, which the assumption seems to be, the path would have led across the reclaimed land from the pit. After a short distance you can turn left across the footbridge to Treharris, or continue onwards towards a series of artificial lakes. The entire length of this path, until the lakes, is lit, and I'm assuming the streetlights were working as they've recently been replaced with modern LED lamps. The river follows the entire length of the path to the left; it would have been pretty much impossible to accidentally enter the river either before or from the bridge as there are barriers. After the bridge the river is gentler (although it still would have been swollen) and the path is still lit, but the barriers between the path and river end. I still imagine it would have been hard to accidentally tumble into the river here, but not impossible. After less than half a mile, at the lakes, the path continues but the streetlights end and the valley becomes very remote. This is not somewhere to be in the dead of night night, not because you're likely to run into any dodgy person but because it's so desolate. I really can't see Brooke having chosen to go here, though.
4) I've seen or heard nothing to suggest Brooke was especially drunk. Nor have I seen or heard anything to suggest she had been unhappy or suffering from mental ill-health. Her Instagram (@brookeemorris_) shows someone who is extremely popular and not outwardly depressed.
5) The "meeting someone" angle is one I hadn't thought of. Parc Taf Bargoed would be the natural choice for someone from Trelewis or Treharris to meet someone away from prying eyes as it's quiet but not remote, but I can't see why a young woman after a night out would choose to meet someone there at 02:40.
6) I've seen or heard nothing to suggest police are looking for anybody else (no "person of interest") but again, also no suggestion that she was either highly intoxicated or suffering emotionally.
7) Xtinalew mentioned that the area is vast and very dangerous but I wouldn't totally agree. It would have been very dangerous to enter the swollen river but the park is mostly a network of paved, lit paths with no cliffs or other steep drops.
nb; this has similarities to another unsolved local case, Billy Davies in 1997. He was last seen near a swollen river, but questions still linger over his total disappearance, as bodies going into rivers in a heavily populated area like the South Wales Valleys tend to turn up. Absolutely impossible that it has any relation to Brooke Morris' disappearance, though, other than possibly the danger of swollen rivers at night.
Also, it turns out the path towards the bridge and on to the lakes is covered on Streetview, starting at the lane from Bontnewydd Terrace she was last seen walking down:
Google Maps