Hello there, I live in El Paso. Although I've never stayed in an RV park here in El Paso, the Mission RV stated above is probably the best looking in the City. Currently there is major freeway construction 24hrs a day really near the intersection of I-10 and Loop 375 where Mission RV is located. You might want to ask them how that is affecting them. If not, I would suggest staying in Las Cruces about 40 miles west of us.
When I first started RVing some years ago I used to frequent Roadrunner quite often for parts, but never felt welcome. I stopped giving them my business long ago. Anyway, their lot always seems to have RVs there.
El Paso is more of a hotel city with plenty nice/inexpensive hotels to choose from right off the I-10 corridor. If staying in El Paso and like Mexican food, try the local and -real- Mexican eateries we have. We have 100s if not 1000s of real Mexican food restaurants and many are the same as found across the border.
Enjoy